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Mies US, Hervé V, Kropp T, Platt K, Sillam-Dussès D, Šobotník J, Brune A. Genome reduction and horizontal gene transfer in the evolution of Endomicrobia-rise and fall of an intracellular symbiosis with termite gut flagellates. mBio 2024; 15:e0082624. [PMID: 38742878 PMCID: PMC11257099 DOI: 10.1128/mbio.00826-24] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2024] [Accepted: 04/09/2024] [Indexed: 05/16/2024] Open
Abstract
Bacterial endosymbionts of eukaryotic hosts typically experience massive genome reduction, but the underlying evolutionary processes are often obscured by the lack of free-living relatives. Endomicrobia, a family-level lineage of host-associated bacteria in the phylum Elusimicrobiota that comprises both free-living representatives and endosymbionts of termite gut flagellates, are an excellent model to study evolution of intracellular symbionts. We reconstructed 67 metagenome-assembled genomes (MAGs) of Endomicrobiaceae among more than 1,700 MAGs from the gut microbiota of a wide range of termites. Phylogenomic analysis confirmed a sister position of representatives from termites and ruminants, and allowed to propose eight new genera in the radiation of Endomicrobiaceae. Comparative genome analysis documented progressive genome erosion in the new genus Endomicrobiellum, which comprises all flagellate endosymbionts characterized to date. Massive gene losses were accompanied by the acquisition of new functions by horizontal gene transfer, which led to a shift from a glucose-based energy metabolism to one based on sugar phosphates. The breakdown of glycolysis and many anabolic pathways for amino acids and cofactors in several subgroups was compensated by the independent acquisition of new uptake systems, including an ATP/ADP antiporter, from other gut microbiota. The putative donors are mostly flagellate endosymbionts from other bacterial phyla, including several, hitherto unknown lineages of uncultured Alphaproteobacteria, documenting the importance of horizontal gene transfer in the convergent evolution of these intracellular symbioses. The loss of almost all biosynthetic capacities in some lineages of Endomicrobiellum suggests that their originally mutualistic relationship with flagellates is on its decline.IMPORTANCEUnicellular eukaryotes are frequently colonized by bacterial and archaeal symbionts. A prominent example are the cellulolytic gut flagellates of termites, which harbor diverse but host-specific bacterial symbionts that occur exclusively in termite guts. One of these lineages, the so-called Endomicrobia, comprises both free-living and endosymbiotic representatives, which offers the unique opportunity to study the evolutionary processes underpinning the transition from a free-living to an intracellular lifestyle. Our results revealed a progressive gene loss in energy metabolism and biosynthetic pathways, compensated by the acquisition of new functions via horizontal gene transfer from other gut bacteria, and suggest the eventual breakdown of an initially mutualistic symbiosis. Evidence for convergent evolution of unrelated endosymbionts reflects adaptations to the intracellular environment of termite gut flagellates.
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Affiliation(s)
- Undine S. Mies
- Research Group Insect Gut Microbiology and Symbiosis, Max Planck Institute for Terrestrial Microbiology, Marburg, Germany
| | - Vincent Hervé
- Research Group Insect Gut Microbiology and Symbiosis, Max Planck Institute for Terrestrial Microbiology, Marburg, Germany
| | - Tom Kropp
- Research Group Insect Gut Microbiology and Symbiosis, Max Planck Institute for Terrestrial Microbiology, Marburg, Germany
| | - Katja Platt
- Research Group Insect Gut Microbiology and Symbiosis, Max Planck Institute for Terrestrial Microbiology, Marburg, Germany
| | - David Sillam-Dussès
- Laboratory of Experimental and Comparative Ethology LEEC, UR 4443, University Sorbonne Paris Nord, Villetaneuse, France
| | - Jan Šobotník
- Faculty of Tropical AgriSciences, Czech University of Life Sciences, Prague, Czechia
- Biology Centre, Czech Academy of Sciences, Institute of Entomology, České Budějovice, Czechia
| | - Andreas Brune
- Research Group Insect Gut Microbiology and Symbiosis, Max Planck Institute for Terrestrial Microbiology, Marburg, Germany
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Gile GH. Protist symbionts of termites: diversity, distribution, and coevolution. Biol Rev Camb Philos Soc 2024; 99:622-652. [PMID: 38105542 DOI: 10.1111/brv.13038] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2023] [Revised: 11/28/2023] [Accepted: 11/30/2023] [Indexed: 12/19/2023]
Abstract
The symbiosis between termites and their hindgut protists is mutually obligate and vertically inherited. It was established by the late Jurassic in the cockroach ancestors of termites as they transitioned to wood feeding. Since then, protist symbionts have been transmitted from host generation to host generation by proctodeal trophallaxis (anal feeding). The protists belong to multiple lineages within the eukaryotic superphylum Metamonada. Most of these lineages have evolved large cells with complex morphology, unlike the non-termite-associated Metamonada. The species richness and taxonomic composition of symbiotic protist communities varies widely across termite lineages, especially within the deep-branching clade Teletisoptera. In general, closely related termites tend to harbour closely related protists, and deep-branching termites tend to harbour deep-branching protists, reflecting their broad-scale co-diversification. A closer view, however, reveals a complex distribution of protist lineages across hosts. Some protist taxa are common, some are rare, some are widespread, and some are restricted to a single host family or genus. Some protist taxa can be found in only a few, distantly related, host species. Thus, the long history of co-diversification in this symbiosis has been complicated by lineage-specific loss of symbionts, transfer of symbionts from one host lineage to another, and by independent diversification of the symbionts relative to their hosts. This review aims to introduce the biology of this important symbiosis and serve as a gateway to the diversity and systematics literature for both termites and protists. A searchable database with all termite-protist occurrence records and taxonomic references is provided as a supplementary file to encourage and facilitate new research in this field.
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Affiliation(s)
- Gillian H Gile
- School of Life Sciences, Arizona State University, Tempe, AZ, 85287, USA
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Chen J, Setia G, Lin LH, Sun Q, Husseneder C. Weight and protozoa number but not bacteria diversity are associated with successful pair formation of dealates in the Formosan subterranean termite, Coptotermes formosanus. PLoS One 2023; 18:e0293813. [PMID: 37956140 PMCID: PMC10642788 DOI: 10.1371/journal.pone.0293813] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2023] [Accepted: 10/19/2023] [Indexed: 11/15/2023] Open
Abstract
New colonies of Formosan subterranean termites are founded by monogamous pairs. During swarming season, alates (winged reproductives) leave their parental colony. After swarming, they drop to the ground, shed their wings, and male and female dealates find suitable nesting sites where they mate and become kings and queens of new colonies. The first generation of offspring is entirely dependent on the nutritional resources of the founder pair consisting of the fat and protein reserves of the dealates and their microbiota, which include the cellulose-digesting protozoa and diverse bacteria. Since termite kings and queens can live for decades, mate for life and colony success is linked to those initial resources, we hypothesized that gut microbiota of founders affect pair formation. To test this hypothesis, we collected pairs found in nest chambers and single male and female dealates from four swarm populations. The association of three factors (pairing status, sex of the dealates and population) with dealate weights, total protozoa, and protozoa Pseudotrichonympha grassii numbers in dealate hindguts was determined. In addition, Illumina 16S rRNA gene sequencing and the QIIME2 pipeline were used to determine the impact of those three factors on gut bacteria diversity of dealates. Here we report that pairing status was significantly affected by weight and total protozoa numbers, but not by P. grassii numbers and bacteria diversity. Weight and total protozoa numbers were higher in paired compared to single dealates. Males contained significantly higher P. grassii numbers and bacteria richness and marginally higher phylogenetic diversity despite having lower weights than females. In conclusion, this study showed that dealates with high body weight and protozoa numbers are more likely to pair and become colony founders, probably because of competitive advantage. The combined nutritional resources provided by body weight and protozoa symbionts of the parents are important for successful colony foundation and development.
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Affiliation(s)
- Junyan Chen
- Department of Entomology, Louisiana State University Agricultural Center, Baton Rouge, Los Angeles, United States of America
| | - Garima Setia
- Department of Entomology, Louisiana State University Agricultural Center, Baton Rouge, Los Angeles, United States of America
| | - Li-Hsiang Lin
- Department of Experimental Statistics, Louisiana State University Agricultural Center, Baton Rouge, Los Angeles, United States of America
| | - Qian Sun
- Department of Entomology, Louisiana State University Agricultural Center, Baton Rouge, Los Angeles, United States of America
| | - Claudia Husseneder
- Department of Entomology, Louisiana State University Agricultural Center, Baton Rouge, Los Angeles, United States of America
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Sinotte VM, Renelies-Hamilton J, Andreu-Sánchez S, Vasseur-Cognet M, Poulsen M. Selective enrichment of founding reproductive microbiomes allows extensive vertical transmission in a fungus-farming termite. Proc Biol Sci 2023; 290:20231559. [PMID: 37848067 PMCID: PMC10581767 DOI: 10.1098/rspb.2023.1559] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2023] [Accepted: 09/09/2023] [Indexed: 10/19/2023] Open
Abstract
Mutualistic coevolution can be mediated by vertical transmission of symbionts between host generations. Termites host complex gut bacterial communities with evolutionary histories indicative of mixed-mode transmission. Here, we document that vertical transmission of gut bacterial strains is congruent across parent to offspring colonies in four pedigrees of the fungus-farming termite Macrotermes natalensis. We show that 44% of the offspring colony microbiome, including more than 80 bacterial genera and pedigree-specific strains, are consistently inherited. We go on to demonstrate that this is achieved because colony-founding reproductives are selectively enriched with a set of non-random, environmentally sensitive and termite-specific gut microbes from their colonies of origin. These symbionts transfer to offspring colony workers with high fidelity, after which priority effects appear to influence the composition of the establishing microbiome. Termite reproductives thus secure transmission of complex communities of specific, co-evolved microbes that are critical to their offspring colonies. Extensive yet imperfect inheritance implies that the maturing colony benefits from acquiring environmental microbes to complement combinations of termite, fungus and vertically transmitted microbes; a mode of transmission that is emerging as a prevailing strategy for hosts to assemble complex adaptive microbiomes.
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Affiliation(s)
- Veronica M. Sinotte
- Section for Ecology and Evolution, Department of Biology, University of Copenhagen, 2100 Copenhagen East, Denmark
- Center for Evolutionary Hologenomics, GLOBE Institute, University of Copenhagen, 1350 Copenhagen K, Denmark
| | - Justinn Renelies-Hamilton
- Section for Ecology and Evolution, Department of Biology, University of Copenhagen, 2100 Copenhagen East, Denmark
| | - Sergio Andreu-Sánchez
- Section for Ecology and Evolution, Department of Biology, University of Copenhagen, 2100 Copenhagen East, Denmark
- Department of Paediatrics, University Medical Centre Groningen, University of Groningen, 9700 RB Groningen, The Netherlands
| | - Mireille Vasseur-Cognet
- UMR IRD 242, UPEC, CNRS 7618, UPMC 113, INRAe 1392, Paris 7 113, Institute of Ecology and Environmental Sciences of Paris, Bondy, France
- Institut National de la Santé et de la Recherche Médicale, Paris, France
| | - Michael Poulsen
- Section for Ecology and Evolution, Department of Biology, University of Copenhagen, 2100 Copenhagen East, Denmark
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Chakraborty A, Šobotník J, Votýpková K, Hradecký J, Stiblik P, Synek J, Bourguignon T, Baldrian P, Engel MS, Novotný V, Odriozola I, Větrovský T. Impact of Wood Age on Termite Microbial Assemblages. Appl Environ Microbiol 2023; 89:e0036123. [PMID: 37067424 PMCID: PMC10231148 DOI: 10.1128/aem.00361-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2023] [Accepted: 03/25/2023] [Indexed: 04/18/2023] Open
Abstract
The decomposition of wood and detritus is challenging to most macroscopic organisms due to the recalcitrant nature of lignocellulose. Moreover, woody plants often protect themselves by synthesizing toxic or nocent compounds which infuse their tissues. Termites are essential wood decomposers in warmer terrestrial ecosystems and, as such, they have to cope with high concentrations of plant toxins in wood. In this paper, we evaluated the influence of wood age on the gut microbial (bacterial and fungal) communities associated with the termites Reticulitermes flavipes (Rhinotermitidae) (Kollar, 1837) and Microcerotermes biroi (Termitidae) (Desneux, 1905). We confirmed that the secondary metabolite concentration decreased with wood age. We identified a core microbial consortium maintained in the gut of R. flavipes and M. biroi and found that its diversity and composition were not altered by the wood age. Therefore, the concentration of secondary metabolites had no effect on the termite gut microbiome. We also found that both termite feeding activities and wood age affect the wood microbiome. Whether the increasing relative abundance of microbes with termite activities is beneficial to the termites is unknown and remains to be investigated. IMPORTANCE Termites can feed on wood thanks to their association with their gut microbes. However, the current understanding of termites as holobiont is limited. To our knowledge, no studies comprehensively reveal the influence of wood age on the termite-associated microbial assemblage. The wood of many tree species contains high concentrations of plant toxins that can vary with their age and may influence microbes. Here, we studied the impact of Norway spruce wood of varying ages and terpene concentrations on the microbial communities associated with the termites Reticulitermes flavipes (Rhinotermitidae) and Microcerotermes biroi (Termitidae). We performed a bacterial 16S rRNA and fungal ITS2 metabarcoding study to reveal the microbial communities associated with R. flavipes and M. biroi and their impact on shaping the wood microbiome. We noted that a stable core microbiome in the termites was unaltered by the feeding substrate, while termite activities influenced the wood microbiome, suggesting that plant secondary metabolites have negligible effects on the termite gut microbiome. Hence, our study shed new insights into the termite-associated microbial assemblage under the influence of varying amounts of terpene content in wood and provides a groundwork for future investigations for developing symbiont-mediated termite control measures.
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Affiliation(s)
- Amrita Chakraborty
- EVA 4.0 Unit, Faculty of Forestry and Wood Sciences, Czech University of Life Sciences, Prague, Czech Republic
| | - Jan Šobotník
- Faculty of Tropical AgriSciences, Czech University of Life Sciences, Prague, Czech Republic
| | - Kateřina Votýpková
- EVA 4.0 Unit, Faculty of Forestry and Wood Sciences, Czech University of Life Sciences, Prague, Czech Republic
| | - Jaromír Hradecký
- Faculty of Forestry and Wood Sciences, Czech University of Life Sciences, Prague, Czech Republic
| | - Petr Stiblik
- EVA 4.0 Unit, Faculty of Forestry and Wood Sciences, Czech University of Life Sciences, Prague, Czech Republic
| | - Jiří Synek
- EVA 4.0 Unit, Faculty of Forestry and Wood Sciences, Czech University of Life Sciences, Prague, Czech Republic
| | - Thomas Bourguignon
- Faculty of Tropical AgriSciences, Czech University of Life Sciences, Prague, Czech Republic
- Okinawa Institute of Science & Technology Graduate University, Okinawa, Japan
| | - Petr Baldrian
- Institute of Microbiology, Czech Academy of Sciences, Prague, Czech Republic
| | - Michael S. Engel
- American Museum of Natural History, New York, New York, USA
- Division of Entomology, Natural History Museum, University of Kansas, Lawrence, Kansas, USA
- Department of Ecology & Evolutionary Biology, University of Kansas, Lawrence, Kansas, USA
| | - Vojtěch Novotný
- Faculty of Science, University of South Bohemia, Ceske Budejovice, Czech Republic
- Biology Centre of the Czech Academy of Sciences, Institute of Entomology, Ceske Budejovice, Czech Republic
| | - Iñaki Odriozola
- Institute of Microbiology, Czech Academy of Sciences, Prague, Czech Republic
| | - Tomáš Větrovský
- EVA 4.0 Unit, Faculty of Forestry and Wood Sciences, Czech University of Life Sciences, Prague, Czech Republic
- Institute of Microbiology, Czech Academy of Sciences, Prague, Czech Republic
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Long rDNA amplicon sequencing of insect-infecting nephridiophagids reveals their affiliation to the Chytridiomycota and a potential to switch between hosts. Sci Rep 2021; 11:396. [PMID: 33431987 PMCID: PMC7801462 DOI: 10.1038/s41598-020-79842-6] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2020] [Accepted: 12/14/2020] [Indexed: 01/29/2023] Open
Abstract
Nephridiophagids are unicellular eukaryotes that parasitize the Malpighian tubules of numerous insects. Their life cycle comprises multinucleate vegetative plasmodia that divide into oligonucleate and uninucleate cells, and sporogonial plasmodia that form uninucleate spores. Nephridiophagids are poor in morphological characteristics, and although they have been tentatively identified as early-branching fungi based on the SSU rRNA gene sequences of three species, their exact position within the fungal tree of live remained unclear. In this study, we describe two new species of nephridiophagids (Nephridiophaga postici and Nephridiophaga javanicae) from cockroaches. Using long-read sequencing of the nearly complete rDNA operon of numerous further species obtained from cockroaches and earwigs to improve the resolution of the phylogenetic analysis, we found a robust affiliation of nephridiophagids with the Chytridiomycota-a group of zoosporic fungi that comprises parasites of diverse host taxa, such as microphytes, plants, and amphibians. The presence of the same nephridiophagid species in two only distantly related cockroaches indicates that their host specificity is not as strict as generally assumed.
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Termites Are Associated with External Species-Specific Bacterial Communities. Appl Environ Microbiol 2021; 87:AEM.02042-20. [PMID: 33097518 DOI: 10.1128/aem.02042-20] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2020] [Accepted: 10/16/2020] [Indexed: 12/28/2022] Open
Abstract
All termites have established a wide range of associations with symbiotic microbes in their guts. Some termite species are also associated with microbes that grow in their nests, but the prevalence of these associations remains largely unknown. Here, we studied the bacterial communities associated with the termites and galleries of three wood-feeding termite species by using 16S rRNA gene amplicon sequencing. We found that the compositions of bacterial communities among termite bodies, termite galleries, and control wood fragments devoid of termite activities differ in a species-specific manner. Termite galleries were enriched in bacterial operational taxonomic units (OTUs) belonging to Rhizobiales and Actinobacteria, which were often shared by several termite species. The abundance of several bacterial OTUs, such as Bacillus, Clostridium, Corynebacterium, and Staphylococcus, was reduced in termite galleries. Our results demonstrate that both termite guts and termite galleries harbor unique bacterial communities.IMPORTANCE As is the case for all ecosystem engineers, termites impact their habitat by their activities, potentially affecting bacterial communities. Here, we studied three wood-feeding termite species and found that they influence the composition of the bacterial communities in their surrounding environment. Termite activities have positive effects on Rhizobiales and Actinobacteria abundance and negative effects on the abundance of several ubiquitous genera, such as Bacillus, Clostridium, Corynebacterium, and Staphylococcus Our results demonstrate that termite galleries harbor unique bacterial communities.
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Oren A, Garrity GM, Parker CT, Chuvochina M, Trujillo ME. Lists of names of prokaryotic Candidatus taxa. Int J Syst Evol Microbiol 2020; 70:3956-4042. [DOI: 10.1099/ijsem.0.003789] [Citation(s) in RCA: 782] [Impact Index Per Article: 195.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023] Open
Abstract
We here present annotated lists of names of Candidatus taxa of prokaryotes with ranks between subspecies and class, proposed between the mid-1990s, when the provisional status of Candidatus taxa was first established, and the end of 2018. Where necessary, corrected names are proposed that comply with the current provisions of the International Code of Nomenclature of Prokaryotes and its Orthography appendix. These lists, as well as updated lists of newly published names of Candidatus taxa with additions and corrections to the current lists to be published periodically in the International Journal of Systematic and Evolutionary Microbiology, may serve as the basis for the valid publication of the Candidatus names if and when the current proposals to expand the type material for naming of prokaryotes to also include gene sequences of yet-uncultivated taxa is accepted by the International Committee on Systematics of Prokaryotes.
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Affiliation(s)
- Aharon Oren
- The Institute of Life Sciences, The Hebrew University of Jerusalem, The Edmond J. Safra Campus, 9190401 Jerusalem, Israel
| | - George M. Garrity
- NamesforLife, LLC, PO Box 769, Okemos MI 48805-0769, USA
- Department of Microbiology & Molecular Genetics, Biomedical Physical Sciences, Michigan State University, East Lansing, MI 48824-4320, USA
| | | | - Maria Chuvochina
- Australian Centre for Ecogenomics, University of Queensland, St. Lucia QLD 4072, Brisbane, Australia
| | - Martha E. Trujillo
- Departamento de Microbiología y Genética, Campus Miguel de Unamuno, Universidad de Salamanca, 37007, Salamanca, Spain
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Michaud C, Hervé V, Dupont S, Dubreuil G, Bézier AM, Meunier J, Brune A, Dedeine F. Efficient but occasionally imperfect vertical transmission of gut mutualistic protists in a wood‐feeding termite. Mol Ecol 2019; 29:308-324. [DOI: 10.1111/mec.15322] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2019] [Revised: 11/26/2019] [Accepted: 11/27/2019] [Indexed: 10/25/2022]
Affiliation(s)
- Caroline Michaud
- Institut de Recherche sur la Biologie de l'Insecte UMR 7261 CNRS – Université de Tours Tours France
| | - Vincent Hervé
- Research Group Insect Gut Microbiology and Symbiosis Max Planck Institute for Terrestrial Microbiology Marburg Germany
| | - Simon Dupont
- Institut de Recherche sur la Biologie de l'Insecte UMR 7261 CNRS – Université de Tours Tours France
| | - Géraldine Dubreuil
- Institut de Recherche sur la Biologie de l'Insecte UMR 7261 CNRS – Université de Tours Tours France
| | - Annie M. Bézier
- Institut de Recherche sur la Biologie de l'Insecte UMR 7261 CNRS – Université de Tours Tours France
| | - Joël Meunier
- Institut de Recherche sur la Biologie de l'Insecte UMR 7261 CNRS – Université de Tours Tours France
| | - Andreas Brune
- Research Group Insect Gut Microbiology and Symbiosis Max Planck Institute for Terrestrial Microbiology Marburg Germany
| | - Franck Dedeine
- Institut de Recherche sur la Biologie de l'Insecte UMR 7261 CNRS – Université de Tours Tours France
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Waidele L, Korb J, Voolstra CR, Dedeine F, Staubach F. Ecological specificity of the metagenome in a set of lower termite species supports contribution of the microbiome to adaptation of the host. Anim Microbiome 2019; 1:13. [PMID: 33499940 PMCID: PMC7807685 DOI: 10.1186/s42523-019-0014-2] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2019] [Accepted: 09/23/2019] [Indexed: 12/27/2022] Open
Abstract
Background Elucidating the interplay between hosts and their microbiomes in ecological adaptation has become a central theme in evolutionary biology. A textbook example of microbiome-mediated adaptation is the adaptation of lower termites to a wood-based diet, as they depend on their gut microbiome to digest wood. Lower termites have further adapted to different life types. Termites of the wood-dwelling life type never leave their nests and feed on a uniform diet. Termites of the foraging life type forage for food outside the nest and have access to other nutrients. Here we sought to investigate whether the microbiome that is involved in food substrate breakdown and nutrient acquisition might contribute to adaptation to these dietary differences. We reasoned that this should leave ecological imprints on the microbiome. Results We investigated the protist and bacterial microbiomes of a total of 29 replicate colonies from five termite species, covering both life types, using metagenomic shotgun sequencing. The microbiome of wood-dwelling species with a uniform wood diet was enriched for genes involved in lignocellulose degradation. Furthermore, metagenomic patterns suggest that the microbiome of wood-dwelling species relied primarily on direct fixation of atmospheric nitrogen, while the microbiome of foraging species entailed the necessary pathways to utilize nitrogen in the form of nitrate for example from soil. Conclusion Our findings are consistent with the notion that the microbiome of wood-dwelling species bears an imprint of its specialization on degrading a uniform wood diet, while the microbiome of the foraging species might reflect its adaption to access growth limiting nutrients from more diverse sources. This supports the idea that specific subsets of functions encoded by the microbiome can contribute to host adaptation.
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Affiliation(s)
- Lena Waidele
- Biologie I, University of Freiburg, Hauptstr. 1, 79104, Freiburg, Germany
| | - Judith Korb
- Biologie I, University of Freiburg, Hauptstr. 1, 79104, Freiburg, Germany
| | | | - Franck Dedeine
- Institut de Recherche sur la Biologie de l'Insecte, UMR 7261, CNRS - Université de Tours, 37200, Tours, France
| | - Fabian Staubach
- Biologie I, University of Freiburg, Hauptstr. 1, 79104, Freiburg, Germany.
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11
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Utami YD, Kuwahara H, Igai K, Murakami T, Sugaya K, Morikawa T, Nagura Y, Yuki M, Deevong P, Inoue T, Kihara K, Lo N, Yamada A, Ohkuma M, Hongoh Y. Genome analyses of uncultured TG2/ZB3 bacteria in 'Margulisbacteria' specifically attached to ectosymbiotic spirochetes of protists in the termite gut. THE ISME JOURNAL 2019; 13:455-467. [PMID: 30287885 PMCID: PMC6331581 DOI: 10.1038/s41396-018-0297-4] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/23/2018] [Revised: 09/20/2018] [Accepted: 09/25/2018] [Indexed: 11/09/2022]
Abstract
We investigated the phylogenetic diversity, localisation and metabolism of an uncultured bacterial clade, Termite Group 2 (TG2), or ZB3, in the termite gut, which belongs to the candidate phylum 'Margulisbacteria'. We performed 16S rRNA amplicon sequencing analysis and detected TG2/ZB3 sequences in 40 out of 72 termite and cockroach species, which exclusively constituted a monophyletic cluster in the TG2/ZB3 clade. Fluorescence in situ hybridisation analysis in lower termites revealed that these bacteria are specifically attached to ectosymbiotic spirochetes of oxymonad gut protists. Draft genomes of four TG2/ZB3 phylotypes from a small number of bacterial cells were reconstructed, and functional genome analysis suggested that these bacteria hydrolyse and ferment cellulose/cellobiose to H2, CO2, acetate and ethanol. We also assembled a draft genome for a partner Treponema spirochete and found that it encoded genes for reductive acetogenesis from H2 and CO2. We hypothesise that the TG2/ZB3 bacteria we report here are commensal or mutualistic symbionts of the spirochetes, exploiting the spirochetes as H2 sinks. For these bacteria, we propose a novel genus, 'Candidatus Termititenax', which represents a hitherto uncharacterised class-level clade in 'Margulisbacteria'. Our findings add another layer, i.e., cellular association between bacteria, to the multi-layered symbiotic system in the termite gut.
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Affiliation(s)
- Yuniar Devi Utami
- Department of Biological Sciences, Tokyo Institute of Technology, Tokyo, 152-8550, Japan
| | - Hirokazu Kuwahara
- Department of Biological Sciences, Tokyo Institute of Technology, Tokyo, 152-8550, Japan
| | - Katsura Igai
- Department of Biological Sciences, Tokyo Institute of Technology, Tokyo, 152-8550, Japan
| | - Takumi Murakami
- Department of Biological Sciences, Tokyo Institute of Technology, Tokyo, 152-8550, Japan
| | - Kaito Sugaya
- Department of Biological Sciences, Tokyo Institute of Technology, Tokyo, 152-8550, Japan
| | - Takahiro Morikawa
- Department of Biological Sciences, Tokyo Institute of Technology, Tokyo, 152-8550, Japan
| | - Yuichi Nagura
- Department of Biological Sciences, Tokyo Institute of Technology, Tokyo, 152-8550, Japan
| | - Masahiro Yuki
- Japan Collection of Microorganisms, RIKEN BioResource Research Center, Tsukuba, 305-0074, Japan
| | - Pinsurang Deevong
- Department of Microbiology, Kasetsart University, Bangkok, 10900, Thailand
| | - Tetsushi Inoue
- Graduate School of Fisheries and Environmental Sciences, Nagasaki University, Nagasaki, 852-8521, Japan
| | - Kumiko Kihara
- Department of Biological Sciences, Tokyo Institute of Technology, Tokyo, 152-8550, Japan
| | - Nathan Lo
- School of Life and Environmental Sciences, The University of Sydney, Sydney, NSW, 2006, Australia
| | - Akinori Yamada
- Department of Biological Sciences, Tokyo Institute of Technology, Tokyo, 152-8550, Japan
- Graduate School of Fisheries and Environmental Sciences, Nagasaki University, Nagasaki, 852-8521, Japan
| | - Moriya Ohkuma
- Japan Collection of Microorganisms, RIKEN BioResource Research Center, Tsukuba, 305-0074, Japan
| | - Yuichi Hongoh
- Department of Biological Sciences, Tokyo Institute of Technology, Tokyo, 152-8550, Japan.
- Japan Collection of Microorganisms, RIKEN BioResource Research Center, Tsukuba, 305-0074, Japan.
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12
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Seah BKB, Schwaha T, Volland JM, Huettel B, Dubilier N, Gruber-Vodicka HR. Specificity in diversity: single origin of a widespread ciliate-bacteria symbiosis. Proc Biol Sci 2018; 284:rspb.2017.0764. [PMID: 28701560 PMCID: PMC5524500 DOI: 10.1098/rspb.2017.0764] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2017] [Accepted: 06/06/2017] [Indexed: 12/03/2022] Open
Abstract
Symbioses between eukaryotes and sulfur-oxidizing (thiotrophic) bacteria have convergently evolved multiple times. Although well described in at least eight classes of metazoan animals, almost nothing is known about the evolution of thiotrophic symbioses in microbial eukaryotes (protists). In this study, we characterized the symbioses between mouthless marine ciliates of the genus Kentrophoros, and their thiotrophic bacteria, using comparative sequence analysis and fluorescence in situ hybridization. Ciliate small-subunit rRNA sequences were obtained from 17 morphospecies collected in the Mediterranean and Caribbean, and symbiont sequences from 13 of these morphospecies. We discovered a new Kentrophoros morphotype where the symbiont-bearing surface is folded into pouch-like compartments, illustrating the variability of the basic body plan. Phylogenetic analyses revealed that all investigated Kentrophoros belonged to a single clade, despite the remarkable morphological diversity of these hosts. The symbionts were also monophyletic and belonged to a new clade within the Gammaproteobacteria, with no known cultured representatives. Each host morphospecies had a distinct symbiont phylotype, and statistical analyses revealed significant support for host–symbiont codiversification. Given that these symbioses were collected from two widely separated oceans, our results indicate that symbiotic associations in unicellular hosts can be highly specific and stable over long periods of evolutionary time.
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Affiliation(s)
- Brandon K B Seah
- Max Planck Institute for Marine Microbiology, Celsiusstraße 1, 28359 Bremen, Germany
| | - Thomas Schwaha
- Department of Integrative Zoology, University of Vienna, Althanstraße 14, 1090 Vienna, Austria
| | - Jean-Marie Volland
- Department of Limnology and Bio-Oceanography, University of Vienna, Althanstraße 14, 1090 Vienna, Austria
| | - Bruno Huettel
- Max Planck Genome Centre Cologne, Max Planck Institute for Plant Breeding Research, Carl-von-Linné-Weg 10, 50829 Cologne, Germany
| | - Nicole Dubilier
- Max Planck Institute for Marine Microbiology, Celsiusstraße 1, 28359 Bremen, Germany.,MARUM, Center for Marine Environmental Sciences, University of Bremen, 28359 Bremen, Germany
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13
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Noda S, Shimizu D, Yuki M, Kitade O, Ohkuma M. Host-Symbiont Cospeciation of Termite-Gut Cellulolytic Protists of the Genera Teranympha and Eucomonympha and their Treponema Endosymbionts. Microbes Environ 2018; 33:26-33. [PMID: 29367472 PMCID: PMC5877339 DOI: 10.1264/jsme2.me17096] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
Abstract
Cellulolytic flagellated protists inhabit the hindgut of termites. They are unique and essential to termites and related wood-feeding cockroaches, enabling host feeding on cellulosic matter. Protists of two genera in the family Teranymphidae (phylum Parabasalia), Eucomonympha and Teranympha, are phylogenetically closely related and harbor intracellular endosymbiotic bacteria from the genus Treponema. In order to obtain a clearer understanding of the evolutionary history of this triplex symbiotic relationship, the molecular phylogenies of the three symbiotic partners, the Teranymphidae protists, their Treponema endosymbionts, and their host termites, were inferred and compared. Strong congruence was observed in the tree topologies of all interacting partners, implying their cospeciating relationships. In contrast, the coevolutionary relationship between the Eucomonympha protists and their endosymbionts was more complex, and evidence of incongruence against cospeciating relationships suggested frequent host switches of the endosymbionts, possibly because multiple Eucomonympha species are present in the same gut community. Similarities in the 16S rRNA and gyrB gene sequences of the endosymbionts were higher among Teranympha spp. (>99.25% and >97.2%, respectively), whereas those between Teranympha and Eucomonympha were lower (<97.1% and <91.9%, respectively). In addition, the endosymbionts of Teranympha spp. formed a phylogenetic clade distinct from those of Eucomonympha spp. Therefore, the endosymbiont species of Teranympha spp., designated here as “Candidatus Treponema teratonymphae”, needs to be classified as a species distinct from the endosymbiont species of Eucomonympha spp.
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Affiliation(s)
- Satoko Noda
- Graduate School of Life and Environmental Sciences, University of Yamanashi
| | - Daichi Shimizu
- Graduate School of Life and Environmental Sciences, University of Yamanashi
| | - Masahiro Yuki
- Biomass Research Platform Team, RIKEN Biomass Engineering Program Cooperation Division, RIKEN Center for Sustainable Resource Science
| | | | - Moriya Ohkuma
- Biomass Research Platform Team, RIKEN Biomass Engineering Program Cooperation Division, RIKEN Center for Sustainable Resource Science.,Japan Collection of Microorganisms, RIKEN BioResource Center
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14
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Tikhe CV, Husseneder C. Metavirome Sequencing of the Termite Gut Reveals the Presence of an Unexplored Bacteriophage Community. Front Microbiol 2018; 8:2548. [PMID: 29354098 PMCID: PMC5759034 DOI: 10.3389/fmicb.2017.02548] [Citation(s) in RCA: 27] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2017] [Accepted: 12/08/2017] [Indexed: 12/25/2022] Open
Abstract
The Formosan subterranean termite; Coptotermes formosanus is nutritionally dependent on the complex and diverse community of bacteria and protozoa in their gut. Although, there have been many studies to decipher the taxonomic and functional diversity of bacterial communities in the guts of termites, their bacteriophages remain unstudied. We sequenced the metavirome of the guts of Formosan subterranean termite workers to study the diversity of bacteriophages and other associated viruses. Results showed that the termites harbor a virome in their gut comprised of varied and previously unknown bacteriophages. Between 87-90% of the predicted dsDNA virus genes by Metavir showed similarity to the tailed bacteriophages (Caudovirales). Many predicted genes from the virome matched to bacterial prophage regions. These data are suggestive of a virome dominated by temperate bacteriophages. We predicted the genomes of seven novel Caudovirales bacteriophages from the termite gut. Three of these predicted bacteriophage genomes were found in high proportions in all the three termite colonies tested. Two bacteriophages are predicted to infect endosymbiotic bacteria of the gut protozoa. The presence of these putative bacteriophages infecting endosymbionts of the gut protozoa, suggests a quadripartite relationship between the termites their symbiotic protozoa, endosymbiotic bacteria of the protozoa and their bacteriophages. Other than Caudovirales, ss-DNA virus related genes were also present in the termite gut. We predicted the genomes of 12 novel Microviridae phages from the termite gut and seven of those possibly represent a new proposed subfamily. Circovirus like genomes were also assembled from the termite gut at lower relative abundance. We predicted 10 novel circovirus genomes in this study. Whether these circoviruses infect the termites remains elusive at the moment. The functional and taxonomical annotations suggest that the termites may harbor a core virome comprised of the bacteriophages infecting endosymbionts of the gut protozoa.
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Affiliation(s)
- Chinmay V Tikhe
- Department of Entomology, Louisiana State University Agricultural Center, Baton Rouge, LA, United States
| | - Claudia Husseneder
- Department of Entomology, Louisiana State University Agricultural Center, Baton Rouge, LA, United States
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15
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Waidele L, Korb J, Voolstra CR, Künzel S, Dedeine F, Staubach F. Differential Ecological Specificity of Protist and Bacterial Microbiomes across a Set of Termite Species. Front Microbiol 2017; 8:2518. [PMID: 29312218 PMCID: PMC5742190 DOI: 10.3389/fmicb.2017.02518] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2017] [Accepted: 12/04/2017] [Indexed: 01/21/2023] Open
Abstract
The gut microbiome of lower termites comprises protists and bacteria that help these insects to digest cellulose and to thrive on wood. The composition of the termite gut microbiome correlates with phylogenetic distance of the animal host and host ecology (diet) in termites collected from their natural environment. However, carryover of transient microbes from host collection sites are an experimental concern and might contribute to the ecological imprints on the termite gut microbiome. Here, we set out to test whether an ecological imprint on the termite gut microbiome remains, when focusing on the persistent microbiome. Therefore, we kept five termite species under strictly controlled dietary conditions and subsequently profiled their protist and bacterial gut microbial communities using 18S and 16S rRNA gene amplicon sequencing. The species differed in their ecology; while three of the investigated species were wood-dwellers that feed on the piece of wood they live in and never leave except for the mating flight, the other two species were foragers that regularly leave their nests to forage for food. Despite these prominent ecological differences, protist microbiome structure aligned with phylogenetic relatedness of termite host species. Conversely, bacterial communities seemed more flexible, suggesting that microbiome structure aligned more strongly with the foraging and wood-dwelling ecologies. Interestingly, protist and bacterial community alpha-diversity correlated, suggesting either putative interactions between protists and bacteria, or that both types of microbes in the termite gut follow shared structuring principles. Taken together, our results add to the notion that bacterial communities are more variable over evolutionary time than protist communities and might react more flexibly to changes in host ecology.
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Affiliation(s)
- Lena Waidele
- Evolutionary Biology and Animal Ecology, Albert Ludwigs University of Freiburg, Freiburg, Germany
| | - Judith Korb
- Evolutionary Biology and Animal Ecology, Albert Ludwigs University of Freiburg, Freiburg, Germany
| | - Christian R Voolstra
- Division of Biological and Environmental Science and Engineering, Red Sea Research Center, King Abdullah University of Science and Technology (KAUST), Thuwal, Saudi Arabia
| | - Sven Künzel
- Max Planck Institute for Evolutionary Biology, Plön, Germany
| | - Franck Dedeine
- Institut de Recherche sur la Biologie de l'Insecte, UMR 7261, Centre National de la Recherche Scientifique - Université de Tours, Tours, France
| | - Fabian Staubach
- Evolutionary Biology and Animal Ecology, Albert Ludwigs University of Freiburg, Freiburg, Germany
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16
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Abstract
As much as vertical transmission of microbial symbionts requires their deep integration into the host reproductive and developmental biology, symbiotic lifestyle might profoundly affect bacterial growth and proliferation. This review describes the reproductive oddities displayed by bacteria associated - more or less intimately - with multicellular eukaryotes.
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Affiliation(s)
- Silvia Bulgheresi
- Department of Ecogenetics & Systems Biology, University of Vienna, Althanstrasse 14, Vienna, 1090, Austria
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17
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Martínez-Aquino A. Phylogenetic framework for coevolutionary studies: a compass for exploring jungles of tangled trees. Curr Zool 2016; 62:393-403. [PMID: 29491928 PMCID: PMC5804275 DOI: 10.1093/cz/zow018] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2015] [Accepted: 11/17/2015] [Indexed: 01/19/2023] Open
Abstract
Phylogenetics is used to detect past evolutionary events, from how species originated to how their ecological interactions with other species arose, which can mirror cophylogenetic patterns. Cophylogenetic reconstructions uncover past ecological relationships between taxa through inferred coevolutionary events on trees, for example, codivergence, duplication, host-switching, and loss. These events can be detected by cophylogenetic analyses based on nodes and the length and branching pattern of the phylogenetic trees of symbiotic associations, for example, host-parasite. In the past 2 decades, algorithms have been developed for cophylogetenic analyses and implemented in different software, for example, statistical congruence index and event-based methods. Based on the combination of these approaches, it is possible to integrate temporal information into cophylogenetical inference, such as estimates of lineage divergence times between 2 taxa, for example, hosts and parasites. Additionally, the advances in phylogenetic biogeography applying methods based on parametric process models and combined Bayesian approaches, can be useful for interpreting coevolutionary histories in a scenario of biogeographical area connectivity through time. This article briefly reviews the basics of parasitology and provides an overview of software packages in cophylogenetic methods. Thus, the objective here is to present a phylogenetic framework for coevolutionary studies, with special emphasis on groups of parasitic organisms. Researchers wishing to undertake phylogeny-based coevolutionary studies can use this review as a "compass" when "walking" through jungles of tangled phylogenetic trees.
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Affiliation(s)
- Andrés Martínez-Aquino
- División Zoología Invertebrados, Museo de La Plata, FCNyM, UNLP, Paseo del Bosque s/n, 1900 La Plata, Argentina
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18
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Genome Evolution and Nitrogen Fixation in Bacterial Ectosymbionts of a Protist Inhabiting Wood-Feeding Cockroaches. Appl Environ Microbiol 2016; 82:4682-4695. [PMID: 27235430 DOI: 10.1128/aem.00611-16] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2016] [Accepted: 05/18/2016] [Indexed: 12/30/2022] Open
Abstract
UNLABELLED By combining genomics and isotope imaging analysis using high-resolution secondary ion mass spectrometry (NanoSIMS), we examined the function and evolution of Bacteroidales ectosymbionts of the protist Barbulanympha from the hindguts of the wood-eating cockroach Cryptocercus punctulatus In particular, we investigated the structure of ectosymbiont genomes, which, in contrast to those of endosymbionts, has been little studied to date, and tested the hypothesis that these ectosymbionts fix nitrogen. Unlike with most obligate endosymbionts, genome reduction has not played a major role in the evolution of the Barbulanympha ectosymbionts. Instead, interaction with the external environment has remained important for this symbiont as genes for synthesis of transporters, outer membrane proteins, lipopolysaccharides, and lipoproteins have been retained. The ectosymbiont genome carried two complete operons for nitrogen fixation, a urea transporter, and a urease, indicating the availability of nitrogen as a driving force behind the symbiosis. NanoSIMS analysis of C. punctulatus hindgut symbionts exposed in vivo to (15)N2 supports the hypothesis that Barbulanympha ectosymbionts are capable of nitrogen fixation. This genomic and in vivo functional investigation of protist ectosymbionts highlights the diversity of evolutionary forces and trajectories that shape symbiotic interactions. IMPORTANCE The ecological and evolutionary importance of symbioses is increasingly clear, but the overall diversity of symbiotic interactions remains poorly explored. In this study, we investigated the evolution and nitrogen fixation capabilities of ectosymbionts attached to the protist Barbulanympha from the hindgut of the wood-eating cockroach Cryptocercus punctulatus In addressing genome evolution of protist ectosymbionts, our data suggest that the ecological pressures influencing the evolution of extracellular symbionts clearly differ from intracellular symbionts and organelles. Using NanoSIMS analysis, we also obtained direct imaging evidence of a specific hindgut microbe playing a role in nitrogen fixation. These results demonstrate the power of combining NanoSIMS and genomics tools for investigating the biology of uncultivable microbes. This investigation paves the way for a more precise understanding of microbial interactions in the hindguts of wood-eating insects and further exploration of the diversity and ecological significance of symbiosis between microbes.
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19
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Zimmermann J, Wentrup C, Sadowski M, Blazejak A, Gruber-Vodicka HR, Kleiner M, Ott JA, Cronholm B, De Wit P, Erséus C, Dubilier N. Closely coupled evolutionary history of ecto- and endosymbionts from two distantly related animal phyla. Mol Ecol 2016; 25:3203-23. [PMID: 26826340 DOI: 10.1111/mec.13554] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2015] [Revised: 12/23/2015] [Accepted: 01/19/2016] [Indexed: 12/21/2022]
Abstract
The level of integration between associated partners can range from ectosymbioses to extracellular and intracellular endosymbioses, and this range has been assumed to reflect a continuum from less intimate to evolutionarily highly stable associations. In this study, we examined the specificity and evolutionary history of marine symbioses in a group of closely related sulphur-oxidizing bacteria, called Candidatus Thiosymbion, that have established ecto- and endosymbioses with two distantly related animal phyla, Nematoda and Annelida. Intriguingly, in the ectosymbiotic associations of stilbonematine nematodes, we observed a high degree of congruence between symbiont and host phylogenies, based on their ribosomal RNA (rRNA) genes. In contrast, for the endosymbioses of gutless phallodriline annelids (oligochaetes), we found only a weak congruence between symbiont and host phylogenies, based on analyses of symbiont 16S rRNA genes and six host genetic markers. The much higher degree of congruence between nematodes and their ectosymbionts compared to those of annelids and their endosymbionts was confirmed by cophylogenetic analyses. These revealed 15 significant codivergence events between stilbonematine nematodes and their ectosymbionts, but only one event between gutless phallodrilines and their endosymbionts. Phylogenetic analyses of 16S rRNA gene sequences from 50 Cand. Thiosymbion species revealed seven well-supported clades that contained both stilbonematine ectosymbionts and phallodriline endosymbionts. This closely coupled evolutionary history of marine ecto- and endosymbionts suggests that switches between symbiotic lifestyles and between the two host phyla occurred multiple times during the evolution of the Cand. Thiosymbion clade, and highlights the remarkable flexibility of these symbiotic bacteria.
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Affiliation(s)
- Judith Zimmermann
- Max Planck Institute for Marine Microbiology, Celsiusstrasse 1, D-28359, Bremen, Germany
| | - Cecilia Wentrup
- Max Planck Institute for Marine Microbiology, Celsiusstrasse 1, D-28359, Bremen, Germany.,Department of Microbiology and Ecosystem Science, Division of Microbial Ecology, University of Vienna, Althanstrasse 14, A-1090, Vienna, Austria
| | - Miriam Sadowski
- Max Planck Institute for Marine Microbiology, Celsiusstrasse 1, D-28359, Bremen, Germany
| | - Anna Blazejak
- Max Planck Institute for Marine Microbiology, Celsiusstrasse 1, D-28359, Bremen, Germany
| | | | - Manuel Kleiner
- Max Planck Institute for Marine Microbiology, Celsiusstrasse 1, D-28359, Bremen, Germany.,Department of Geoscience, University of Calgary, Calgary, 2500 University Drive, AB, T2N 1N4, Canada
| | - Jörg A Ott
- Department of Limnology and Oceanography, University of Vienna, Althanstrasse 14, A-1090, Vienna, Austria
| | - Bodil Cronholm
- Department of Bioinformatics and Genetics, Swedish Museum of Natural History, Box 50007, SE-104 05, Stockholm, Sweden
| | - Pierre De Wit
- Department of Marine Sciences, Sven Lovén Centre for Marine Sciences Tjärnö, University of Gothenburg, Hättebäcksvägen 7, SE-452 96, Strömstad, Sweden
| | - Christer Erséus
- Department of Biological and Environmental Sciences, University of Gothenburg, Box 463, SE-405 30, Göteborg, Sweden
| | - Nicole Dubilier
- Max Planck Institute for Marine Microbiology, Celsiusstrasse 1, D-28359, Bremen, Germany.,Faculty of Biology/Chemistry, University of Bremen, Bibliothekstrasse 1, D-28359, Bremen, Germany
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20
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Ohkuma M, Noda S, Hattori S, Iida T, Yuki M, Starns D, Inoue JI, Darby AC, Hongoh Y. Acetogenesis from H2 plus CO2 and nitrogen fixation by an endosymbiotic spirochete of a termite-gut cellulolytic protist. Proc Natl Acad Sci U S A 2015; 112:10224-30. [PMID: 25979941 PMCID: PMC4547241 DOI: 10.1073/pnas.1423979112] [Citation(s) in RCA: 65] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023] Open
Abstract
Symbiotic associations of cellulolytic eukaryotic protists and diverse bacteria are common in the gut microbial communities of termites. Besides cellulose degradation by the gut protists, reductive acetogenesis from H2 plus CO2 and nitrogen fixation by gut bacteria play crucial roles in the host termites' nutrition by contributing to the energy demand of termites and supplying nitrogen poor in their diet, respectively. Fractionation of these activities and the identification of key genes from the gut community of the wood-feeding termite Hodotermopsis sjoestedti revealed that substantial activities in the gut--nearly 60% of reductive acetogenesis and almost exclusively for nitrogen fixation--were uniquely attributed to the endosymbiotic bacteria of the cellulolytic protist in the genus Eucomonympha. The rod-shaped endosymbionts were surprisingly identified as a spirochete species in the genus Treponema, which usually exhibits a characteristic spiral morphology. The endosymbionts likely use H2 produced by the protist for these dual functions. Although H2 is known to inhibit nitrogen fixation in some bacteria, it seemed to rather stimulate this important mutualistic process. In addition, the single-cell genome analyses revealed the endosymbiont's potentials of the utilization of sugars for its energy requirement, and of the biosynthesis of valuable nutrients such as amino acids from the fixed nitrogen. These metabolic interactions are suitable for the dual functions of the endosymbiont and reconcile its substantial contributions in the gut.
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Affiliation(s)
- Moriya Ohkuma
- Japan Collection of Microorganisms/Microbe Division, RIKEN BioResource Center, and Biomass Research Platform Team, RIKEN Biomass Engineering Program Cooperation Division, RIKEN Center for Sustainable Resource Science, Ibaraki 305-0074, Japan;
| | - Satoko Noda
- Japan Collection of Microorganisms/Microbe Division, RIKEN BioResource Center, and Interdisciplinary Graduate School of Medicine and Engineering, University of Yamanashi, Yamanashi 400-8511, Japan
| | - Satoshi Hattori
- Department of Food, Life, and Environmental Sciences, Yamagata University, Yamagata 997-8555, Japan
| | - Toshiya Iida
- Japan Collection of Microorganisms/Microbe Division, RIKEN BioResource Center, and
| | - Masahiro Yuki
- Biomass Research Platform Team, RIKEN Biomass Engineering Program Cooperation Division, RIKEN Center for Sustainable Resource Science, Ibaraki 305-0074, Japan
| | - David Starns
- Japan Collection of Microorganisms/Microbe Division, RIKEN BioResource Center, and Institute of Integrative Biology, University of Liverpool, Liverpool L69 7ZB, United Kingdom; and
| | - Jun-ichi Inoue
- Japan Collection of Microorganisms/Microbe Division, RIKEN BioResource Center, and
| | - Alistair C Darby
- Institute of Integrative Biology, University of Liverpool, Liverpool L69 7ZB, United Kingdom; and
| | - Yuichi Hongoh
- Japan Collection of Microorganisms/Microbe Division, RIKEN BioResource Center, and Department of Biological Sciences, Tokyo Institute of Technology, Tokyo 152-8550, Japan
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21
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Inoue JI, Oshima K, Suda W, Sakamoto M, Iino T, Noda S, Hongoh Y, Hattori M, Ohkuma M. Distribution and evolution of nitrogen fixation genes in the phylum Bacteroidetes. Microbes Environ 2015; 30:44-50. [PMID: 25736980 PMCID: PMC4356463 DOI: 10.1264/jsme2.me14142] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Diazotrophs had not previously been identified among bacterial species in the phylum Bacteroidetes until the rapid expansion of bacterial genome sequences, which revealed the presence of nitrogen fixation (nif) genes in this phylum. We herein determined the draft genome sequences of Bacteroides graminisolvens JCM 15093(T) and Geofilum rubicundum JCM 15548(T). In addition to these and previously reported 'Candidatus Azobacteroides pseudotrichonymphae' and Paludibacter propionicigenes, an extensive survey of the genome sequences of diverse Bacteroidetes members revealed the presence of a set of nif genes (nifHDKENB) in strains of Dysgonomonas gadei, Dysgonomonas capnocytophagoides, Saccharicrinis fermentans, and Alkaliflexus imshenetskii. These eight species belonged to and were distributed sporadically within the order Bacteroidales. Acetylene reduction activity was detected in the five species examined, strongly suggesting their diazotrophic nature. Phylogenetic analyses showed monophyletic clustering of the six Nif protein sequences in the eight Bacteroidales species, implying that nitrogen fixation is ancestral to Bacteroidales and has been retained in these species, but lost in many other lineages. The identification of nif genes in Bacteroidales facilitates the prediction of the organismal origins of related sequences directly obtained from various environments.
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Affiliation(s)
- Jun-ichi Inoue
- Japan Collection of Microorganisms/Microbe Division, RIKEN BioResource Center, Koyadai 3–1–1, Tsukuba, Ibaraki 305–0074, Japan; Synaptech Co. Ltd., Ohte 1–2–37–C–105, Kofu, Yamanashi 400–0015, Japan
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22
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The role of host phylogeny varies in shaping microbial diversity in the hindguts of lower termites. Appl Environ Microbiol 2014; 81:1059-70. [PMID: 25452280 DOI: 10.1128/aem.02945-14] [Citation(s) in RCA: 61] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The hindguts of lower termites and Cryptocercus cockroaches are home to a distinct community of archaea, bacteria, and protists (primarily parabasalids and some oxymonads). Within a host species, the composition of these hindgut communities appears relatively stable, but the evolutionary and ecological factors structuring community composition and stability are poorly understood, as are differential impacts of these factors on protists, bacteria, and archaea. We analyzed the microbial composition of parabasalids and bacteria in the hindguts of Cryptocercus punctulatus and 23 species spanning 4 families of lower termites by pyrosequencing variable regions of the small-subunit rRNA gene. Especially for the parabasalids, these data revealed undiscovered taxa and provided a phylogenetic basis for a more accurate understanding of diversity, diversification, and community composition. The composition of the parabasalid communities was found to be strongly structured by the phylogeny of their hosts, indicating the importance of historical effects, although exceptions were also identified. Particularly, spirotrichonymphids and trichonymphids likely were transferred between host lineages. In contrast, host phylogeny was not sufficient to explain the majority of bacterial community composition, but the compositions of the Bacteroidetes, Elusimicrobia, Tenericutes, Spirochaetes, and Synergistes were structured by host phylogeny perhaps due to their symbiotic associations with protists. All together, historical effects probably resulting from vertical inheritance have had a prominent role in structuring the hindgut communities, especially of the parabasalids, but dispersal and environmental acquisition have played a larger role in community composition than previously expected.
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23
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The cockroach origin of the termite gut microbiota: patterns in bacterial community structure reflect major evolutionary events. Appl Environ Microbiol 2014; 80:2261-9. [PMID: 24487532 DOI: 10.1128/aem.04206-13] [Citation(s) in RCA: 166] [Impact Index Per Article: 16.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
Termites digest wood and other lignocellulosic substrates with the help of their intestinal microbiota. While the functions of the symbionts in the digestive process are slowly emerging, the origin of the bacteria colonizing the hindgut bioreactor is entirely unknown. Recently, our group discovered numerous representatives of bacterial lineages specific to termite guts in a closely related omnivorous cockroach, but it remains unclear whether they derive from the microbiota of a common ancestor or were independently selected by the gut environment. Here, we studied the bacterial gut microbiota in 34 species of termites and cockroaches using pyrotag analysis of the 16S rRNA genes. Although the community structures differed greatly between the major host groups, with dramatic changes in the relative abundances of particular bacterial taxa, we found that the majority of sequence reads belonged to bacterial lineages that were shared among most host species. When mapped onto the host tree, the changes in community structure coincided with major events in termite evolution, such as acquisition and loss of cellulolytic protists and the ensuing dietary diversification. UniFrac analysis of the core microbiota of termites and cockroaches and construction of phylogenetic tree of individual genus level lineages revealed a general host signal, whereas the branching order often did not match the detailed phylogeny of the host. It remains unclear whether the lineages in question have been associated with the ancestral cockroach since the early Cretaceous (cospeciation) or are diet-specific lineages that were independently acquired from the environment (host selection).
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Intranuclear verrucomicrobial symbionts and evidence of lateral gene transfer to the host protist in the termite gut. ISME JOURNAL 2013; 8:1008-19. [PMID: 24335826 DOI: 10.1038/ismej.2013.222] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/11/2013] [Revised: 10/23/2013] [Accepted: 11/07/2013] [Indexed: 11/09/2022]
Abstract
In 1944, Harold Kirby described microorganisms living within nuclei of the protists Trichonympha in guts of termites; however, their taxonomic assignment remains to be accomplished. Here, we identified intranuclear symbionts of Trichonympha agilis in the gut of the termite Reticulitermes speratus. We isolated single nuclei of T. agilis, performed whole-genome amplification, and obtained bacterial 16S rRNA genes by PCR. Unexpectedly, however, all of the analyzed clones were from pseudogenes of 16S rRNA with large deletions and numerous sequence variations even within a single-nucleus sample. Authentic 16S rRNA gene sequences were finally recovered by digesting the nuclear DNA; these pseudogenes were present on the host Trichonympha genome. The authentic sequences represented two distinct bacterial species belonging to the phylum Verrucomicrobia, and the pseudogenes have originated from each of the two species. Fluorescence in situ hybridization confirmed that both species are specifically localized, and occasionally co-localized, within nuclei of T. agilis. Transmission electron microscopy revealed that they are distorted cocci with characteristic electron-dense and lucent regions, which resemble the intranuclear symbionts illustrated by Kirby. For these symbionts, we propose a novel genus and species, 'Candidatus Nucleococcus trichonymphae' and 'Candidatus Nucleococcus kirbyi'. These formed a termite-specific cluster with database sequences, other members of which were also detected within nuclei of various gut protists, including both parabasalids and oxymonads. We suggest that this group is widely distributed as intranuclear symbionts of diverse protists in termite guts and that they might have affected the evolution of the host genome through lateral gene transfer.
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de Vienne DM, Refrégier G, López-Villavicencio M, Tellier A, Hood ME, Giraud T. Cospeciation vs host-shift speciation: methods for testing, evidence from natural associations and relation to coevolution. THE NEW PHYTOLOGIST 2013; 198:347-385. [PMID: 23437795 DOI: 10.1111/nph.12150] [Citation(s) in RCA: 259] [Impact Index Per Article: 23.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/22/2012] [Accepted: 12/19/2012] [Indexed: 05/26/2023]
Abstract
Hosts and their symbionts are involved in intimate physiological and ecological interactions. The impact of these interactions on the evolution of each partner depends on the time-scale considered. Short-term dynamics - 'coevolution' in the narrow sense - has been reviewed elsewhere. We focus here on the long-term evolutionary dynamics of cospeciation and speciation following host shifts. Whether hosts and their symbionts speciate in parallel, by cospeciation, or through host shifts, is a key issue in host-symbiont evolution. In this review, we first outline approaches to compare divergence between pairwise associated groups of species, their advantages and pitfalls. We then consider recent insights into the long-term evolution of host-parasite and host-mutualist associations by critically reviewing the literature. We show that convincing cases of cospeciation are rare (7%) and that cophylogenetic methods overestimate the occurrence of such events. Finally, we examine the relationships between short-term coevolutionary dynamics and long-term patterns of diversification in host-symbiont associations. We review theoretical and experimental studies showing that short-term dynamics can foster parasite specialization, but that these events can occur following host shifts and do not necessarily involve cospeciation. Overall, there is now substantial evidence to suggest that coevolutionary dynamics of hosts and parasites do not favor long-term cospeciation.
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Affiliation(s)
- D M de Vienne
- Centre for Genomic Regulation (CRG), Dr. Aiguader 88, 08003, Barcelona, Spain
- Universitat Pompeu Fabra (UPF), 08003, Barcelona, Spain
| | - G Refrégier
- Université Paris-Sud, Institut de Génétique et Microbiologie, UMR 8621, 91405, Orsay, France
- CNRS, UMR8621, 91405, Orsay, France
| | - M López-Villavicencio
- Muséum National d'Histoire Naturelle, 57 rue Cuvier, F-75231, Paris Cedex 05, France
| | - A Tellier
- Section of Population Genetics, Center of Life and Food Sciences Weihenstephan, Technische Universität München, D-85354, Freising, Germany
| | - M E Hood
- Department of Biology, Amherst College, Amherst, MA, USA
| | - T Giraud
- Université Paris-Sud, Ecologie, Systématique et Evolution, UMR 8079, 91405, Orsay, France
- CNRS, UMR8079, 91405, Orsay, France
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Zhang X, Leadbetter JR. Evidence for cascades of perturbation and adaptation in the metabolic genes of higher termite gut symbionts. mBio 2012; 3:e00223-12. [PMID: 22911968 PMCID: PMC3428693 DOI: 10.1128/mbio.00223-12] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2012] [Accepted: 07/16/2012] [Indexed: 11/29/2022] Open
Abstract
UNLABELLED Termites and their gut microbes engage in fascinating dietary mutualisms. Less is known about how these complex symbioses have evolved after first emerging in an insect ancestor over 120 million years ago. Here we examined a bacterial gene, formate dehydrogenase (fdhF), that is key to the mutualism in 8 species of "higher" termite (members of the Termitidae, the youngest and most biomass-abundant and species-rich termite family). Patterns of fdhF diversity in the gut communities of higher termites contrasted strongly with patterns in less-derived (more-primitive) insect relatives (wood-feeding "lower" termites and roaches). We observed phylogenetic evidence for (i) the sweeping loss of several clades of fdhF that may reflect extinctions of symbiotic protozoa and, importantly, bacteria dependent on them in the last common ancestor of all higher termites and (ii) a radiation of genes from the (possibly) single allele that survived. Sweeping gene loss also resulted in (iii) the elimination of an entire clade of genes encoding selenium (Se)-independent enzymes from higher termite gut communities, perhaps reflecting behavioral or morphological innovations in higher termites that relaxed preexisting environmental limitations of Se, a dietary trace element. Curiously, several higher termite gut communities may have subsequently reencountered Se limitation, reinventing genes for Se-independent proteins via convergent evolution. Lastly, the presence of a novel fdhF lineage within litter-feeding and subterranean higher (but not other) termites may indicate recent gene "invasion" events. These results imply that cascades of perturbation and adaptation by distinct evolutionary mechanisms have impacted the evolution of complex microbial communities in a highly successful lineage of insects. IMPORTANCE Since patterns of relatedness between termite hosts are broadly mirrored by the relatedness of their symbiotic gut microbiota, coevolution between hosts and gut symbionts is rightly considered an important force that has shaped dietary mutualism since its inception over 120 million years ago. Apart from that concerning lateral gene or symbiont transfer between termite gut communities (for which no evidence yet exists), there has been little discussion of alternative mechanisms impacting the evolution of mutualism. Here we provide strong gene-based evidence for past environmental perturbations creating significant upheavals that continue to reverberate throughout the gut communities of species comprising a single termite lineage. We suggest that symbiont extinction events, sweeping gene losses, evolutionary radiations, relaxation and reemergence of key nutritional pressures, convergent evolution of similar traits, and recent gene invasions have all shaped gene composition in the symbiotic gut microbial communities of higher termites, currently the most dominant and successful termite family on Earth.
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Affiliation(s)
- Xinning Zhang
- Environmental Science and Technology, California Institute of Technology, Pasadena, California, USA
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Noda S, Mantini C, Meloni D, Inoue JI, Kitade O, Viscogliosi E, Ohkuma M. Molecular phylogeny and evolution of parabasalia with improved taxon sampling and new protein markers of actin and elongation factor-1α. PLoS One 2012; 7:e29938. [PMID: 22253832 PMCID: PMC3253790 DOI: 10.1371/journal.pone.0029938] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2011] [Accepted: 12/08/2011] [Indexed: 11/27/2022] Open
Abstract
Background Inferring the evolutionary history of phylogenetically isolated, deep-branching groups of taxa—in particular determining the root—is often extraordinarily difficult because their close relatives are unavailable as suitable outgroups. One of these taxonomic groups is the phylum Parabasalia, which comprises morphologically diverse species of flagellated protists of ecological, medical, and evolutionary significance. Indeed, previous molecular phylogenetic analyses of members of this phylum have yielded conflicting and possibly erroneous inferences. Furthermore, many species of Parabasalia are symbionts in the gut of termites and cockroaches or parasites and therefore formidably difficult to cultivate, rendering available data insufficient. Increasing the numbers of examined taxa and informative characters (e.g., genes) is likely to produce more reliable inferences. Principal Findings Actin and elongation factor-1α genes were identified newly from 22 species of termite-gut symbionts through careful manipulations and seven cultured species, which covered major lineages of Parabasalia. Their protein sequences were concatenated and analyzed with sequences of previously and newly identified glyceraldehyde-3-phosphate dehydrogenase and the small-subunit rRNA gene. This concatenated dataset provided more robust phylogenetic relationships among major groups of Parabasalia and a more plausible new root position than those previously reported. Conclusions/Significance We conclude that increasing the number of sampled taxa as well as the addition of new sequences greatly improves the accuracy and robustness of the phylogenetic inference. A morphologically simple cell is likely the ancient form in Parabasalia as opposed to a cell with elaborate flagellar and cytoskeletal structures, which was defined as most basal in previous inferences. Nevertheless, the evolution of Parabasalia is complex owing to several independent multiplication and simplification events in these structures. Therefore, systematics based solely on morphology does not reflect the evolutionary history of parabasalids.
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Affiliation(s)
- Satoko Noda
- Microbe Division/Japan Collection of Microorganisms, RIKEN BioResource Center, Wako, Saitama, Japan
- Interdisciplinary Graduate School of Medicine and Engineering, University of Yamanashi, Kofu, Yamanashi, Japan
- * E-mail: (SN); (MO)
| | - Cléa Mantini
- Center for Infection and Immunity of Lille, Institut Pasteur de Lille, Lille, France, and Inserm U1019, CNRS UMR 8204, and University Lille – Nord de France, Lille, France
| | - Dionigia Meloni
- Center for Infection and Immunity of Lille, Institut Pasteur de Lille, Lille, France, and Inserm U1019, CNRS UMR 8204, and University Lille – Nord de France, Lille, France
- Department of Biomedical Sciences, Division of Experimental and Clinical Microbiology, University of Sassari, Sassari, Italy
| | - Jun-Ichi Inoue
- Microbe Division/Japan Collection of Microorganisms, RIKEN BioResource Center, Wako, Saitama, Japan
| | - Osamu Kitade
- Natural History Laboratory, College of Science, Ibaraki University, Mito, Ibaraki, Japan
| | - Eric Viscogliosi
- Center for Infection and Immunity of Lille, Institut Pasteur de Lille, Lille, France, and Inserm U1019, CNRS UMR 8204, and University Lille – Nord de France, Lille, France
| | - Moriya Ohkuma
- Microbe Division/Japan Collection of Microorganisms, RIKEN BioResource Center, Wako, Saitama, Japan
- * E-mail: (SN); (MO)
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Bacteroidales ectosymbionts of gut flagellates shape the nitrogen-fixing community in dry-wood termites. ISME JOURNAL 2011; 6:1302-13. [PMID: 22189498 DOI: 10.1038/ismej.2011.194] [Citation(s) in RCA: 66] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Although it is well documented that the lack of nitrogen in the diet of wood-feeding termites is compensated by the nitrogen-fixing capacity of their gut microbiota, the bacteria responsible for this activity are largely unknown. Here, we analyzed the diversity and expression of nitrogenase genes (homologs of nifH) in four species of dry-wood termites (Kalotermitidae), which thrive on a particularly nitrogen-poor resource. Although each species harbored a highly diverse suite of termite-specific homologs in their microliter-sized hindgut, only a core set related to nifH genes of Treponema and Azoarcus spp., 'Azobacteroides pseudotrichonymphae', the first member of the Bacteroidales identified as a diazotroph, and termite-gut-specific anfH genes of hitherto unknown origin were preferentially expressed. Transcription patterns corroborated that the populations of active diazotrophs differ fundamentally between termite genera. Capillary-picked suspensions of the flagellates Devescovina arta and Snyderella tabogae revealed that their bacterial ectosymbionts each possess two paralogs of nifH, which apparently have been acquired consecutively during evolution of Bacteroidales, but only one of them (anfH) is actively expressed. Transcription patterns correlated neither with the molybdenum content of the diet nor with intestinal hydrogen concentrations, measured with microsensors. We propose that the nitrogen-fixing community in different dry-wood termites is shaped by the symbionts of their specific flagellate populations. Our findings suggest that the diazotrophic nature of 'Armantifilum devescovinae' has an important role in the nitrogen metabolism of dry-wood termites and is the driving force of co-evolution with its flagellate host.
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Gile GH, James ER, Scheffrahn RH, Carpenter KJ, Harper JT, Keeling PJ. Molecular and morphological analysis of the family Calonymphidae with a description of Calonympha chia sp. nov., Snyderella kirbyi sp. nov., Snyderella swezyae sp. nov. and Snyderella yamini sp. nov. Int J Syst Evol Microbiol 2011; 61:2547-2558. [DOI: 10.1099/ijs.0.028480-0] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Calonymphids are a group of multinucleate, multiflagellate protists belonging to the order Cristamonadida (Parabasalia) that are found exclusively in the hindgut of termites from the family Kalotermitidae. Despite their impressive morphological complexity and diversity, few species have been formally described and fewer still have been characterized at the molecular level. In this study, four novel species of calonymphids were isolated and characterized: Calonympha chia and Snyderella yamini spp. nov., from Neotermes castaneus and Calcaritermes nearcticus from Florida, USA, and Snyderella kirbyi and Snyderella swezyae, spp. nov., from Calcaritermes nigriceps and Cryptotermes cylindroceps from Colombia. Each of these species was distinguished from its congeners by residing in a distinct host and by differences at the molecular level. Phylogenetic analyses of small subunit (SSU) rDNA indicated that the genera Calonympha and Stephanonympha were probably not monophyletic, though the genus Snyderella, previously only represented by one sequence in molecular analyses, appeared with these new data to be monophyletic. This was in keeping with the traditional evolutionary view of the group in which the morphology of the genus Snyderella is considered to be derived, while that of the genus Stephanonympha is ancestral and therefore probably plesiomorphic.
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Affiliation(s)
- Gillian H. Gile
- Department of Botany, University of British Columbia, 3529-6270 University Boulevard, Vancouver, BC V6T 1Z4, Canada
| | - Erick R. James
- Department of Botany, University of British Columbia, 3529-6270 University Boulevard, Vancouver, BC V6T 1Z4, Canada
| | - Rudolf H. Scheffrahn
- University of Florida Research & Education Center, 3205 College Avenue, Davie, FL 33314, USA
| | - Kevin J. Carpenter
- Department of Botany, University of British Columbia, 3529-6270 University Boulevard, Vancouver, BC V6T 1Z4, Canada
| | - James T. Harper
- Department of Biology, Douglas College, 700 Royal Avenue, New Westminster, BC V3M 5Z5, Canada
- Department of Botany, University of British Columbia, 3529-6270 University Boulevard, Vancouver, BC V6T 1Z4, Canada
| | - Patrick J. Keeling
- Department of Botany, University of British Columbia, 3529-6270 University Boulevard, Vancouver, BC V6T 1Z4, Canada
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Hongoh Y. Toward the functional analysis of uncultivable, symbiotic microorganisms in the termite gut. Cell Mol Life Sci 2011; 68:1311-25. [PMID: 21365277 PMCID: PMC11114660 DOI: 10.1007/s00018-011-0648-z] [Citation(s) in RCA: 123] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2011] [Revised: 02/15/2011] [Accepted: 02/15/2011] [Indexed: 11/29/2022]
Abstract
Termites thrive on dead plant matters with the aid of microorganisms resident in their gut. The gut microbiota comprises protists (single-celled eukaryotes), bacteria, and archaea, most of which are unique to the termite gut ecosystem. Although this symbiosis has long been intriguing researchers of both basic and applied sciences, its detailed mechanism remains unclear due to the enormous complexity and the unculturability of the microbiota. In the effort to overcome the difficulty, recent advances in omics, such as metagenomics, metatranscriptomics, and metaproteomics have gradually unveiled the black box of this symbiotic system. Genomics targeting a single species of the unculturable microbial members has also provided a great progress in the understanding of the symbiotic interrelationships among the gut microorganisms. In this review, the symbiotic system organized by wood-feeding termites and their gut microorganisms is outlined, focusing on the recent achievement in omics studies of this multilayered symbiotic system.
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Affiliation(s)
- Yuichi Hongoh
- Department of Biological Sciences, Graduate School of Bioscience and Biotechnology, Tokyo Institute of Technology, Tokyo, Japan.
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Ikeda-Ohtsubo W, Faivre N, Brune A. Putatively free-living 'Endomicrobia'- ancestors of the intracellular symbionts of termite gut flagellates? ENVIRONMENTAL MICROBIOLOGY REPORTS 2010; 2:554-9. [PMID: 23766225 DOI: 10.1111/j.1758-2229.2009.00124.x] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/25/2023]
Abstract
Endomicrobia represent a candidate class in the Elusimicrobia phylum (formerly Termite Group 1) and were originally described as obligate intracellular symbionts of gut flagellates in lower termites. However, 16S rRNA gene sequences of Endomicrobia have been detected also in the gut of insects that do not possess such flagellates, e.g. higher termites and cockroaches. When we eliminated the large gut flagellates of Reticulitermes santonensis by feeding a starch diet, we discovered novel lineages of Endomicrobia that were hitherto undetected in normally faunated specimens. The new phylotypes are clearly separated from the endosymbionts of gut flagellates and fall into the radiation of those from flagellate-free insects. Comprehensive phylogenetic analysis documented that Endomicrobia comprise an apical cluster of endosymbionts that is not necessarily monophyletic and several apparently basal lineages that include bacteria present in the gut of defaunated lower termites, the naturally flagellate-free guts of higher termites and scarab beetle larvae, and in the cow rumen. We propose that these lineages represent hitherto undetected free-living Endomicrobia that share a common ancestor with the intracellular symbionts.
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Affiliation(s)
- Wakako Ikeda-Ohtsubo
- Max-Planck-Institut für terrestrische Mikrobiologie, Karl-von-Frisch-Strasse, 35043 Marburg, Germany
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Diversity and genomes of uncultured microbial symbionts in the termite gut. Biosci Biotechnol Biochem 2010; 74:1145-51. [PMID: 20530908 DOI: 10.1271/bbb.100094] [Citation(s) in RCA: 114] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Termites play a key role in the global carbon cycle as decomposers. Their ability to thrive solely on dead plant matter is chiefly attributable to the activities of gut microbes, which comprise protists, bacteria, and archaea. Although the majority of the gut microbes are as yet unculturable, molecular analyses have gradually been revealing their diversity and symbiotic mechanisms. Culture-independent studies indicate that a single termite species harbors several hundred species of gut microbes unique to termites, and that the microbiota is consistent within a host termite species. To elucidate the functions of these unculturable symbionts, environmental genomics has recently been applied. Particularly, single-species-targeting metagenomics has provided a breakthrough in the understanding of symbiotic roles, such as the nitrogen fixation, of uncultured, individual microbial species. A combination of single-species-targeting metagenomics, conventional metagenomics, and metatranscriptomics should be a powerful tool to dissect this complex, multi-layered symbiotic system.
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Termite Gut Flagellates and Their Methanogenic and Eubacterial Symbionts. (ENDO)SYMBIOTIC METHANOGENIC ARCHAEA 2010. [DOI: 10.1007/978-3-642-13615-3_5] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
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