1
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Marzonie MR, Nitschke MR, Bay LK, Bourne DG, Harrison HB. Symbiodiniaceae diversity varies by host and environment across thermally distinct reefs. Mol Ecol 2024; 33:e17342. [PMID: 38584356 DOI: 10.1111/mec.17342] [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: 08/03/2023] [Revised: 02/07/2024] [Accepted: 03/07/2024] [Indexed: 04/09/2024]
Abstract
Endosymbiotic dinoflagellates (Symbiodiniaceae) influence coral thermal tolerance at both local and regional scales. In isolation, the effects of host genetics, environment, and thermal disturbances on symbiont communities are well understood, yet their combined effects remain poorly resolved. Here, we investigate Symbiodiniaceae across 1300 km in Australia's Coral Sea Marine Park to disentangle these interactive effects. We identified Symbiodiniaceae to species-level resolution for three coral species (Acropora cf humilis, Pocillopora verrucosa, and Pocillopora meandrina) by sequencing two genetic markers of the symbiont (ITS2 and psbAncr), paired with genotype-by-sequencing of the coral host (DArT-seq). Our samples predominantly returned sequences from the genus Cladocopium, where Acropora cf humilis affiliated with C3k, Pocillopora verrucosa with C. pacificum, and Pocillopora meandrina with C. latusorum. Multivariate analyses revealed that Acropora symbionts were driven strongly by local environment and thermal disturbances. In contrast, Pocillopora symbiont communities were both partitioned 2.5-fold more by host genetic structure than by environmental structure. Among the two Pocillopora species, the effects of environment and host genetics explained four times more variation in symbionts for P. meandrina than P. verrucosa. The concurrent bleaching event in 2020 had variable impacts on symbiont communities, consistent with patterns in P. verrucosa and A. cf humilis, but not P. meandrina. Our findings demonstrate how symbiont macroscale community structure responses to environmental gradients depend on host species and their respective population structure. Integrating host, symbiont, and environmental data will help forecast the adaptive potential of corals and their symbionts amidst a rapidly changing environment.
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Affiliation(s)
- Magena R Marzonie
- College of Science and Engineering, James Cook University, Townsville, Queensland, Australia
- Australian Institute of Marine Science, Townsville, Queensland, Australia
- AIMS@JCU, Townsville, Queensland, Australia
| | - Matthew R Nitschke
- Australian Institute of Marine Science, Townsville, Queensland, Australia
- School of Biological Sciences, Victoria University of Wellington, Wellington, New Zealand
| | - Line K Bay
- Australian Institute of Marine Science, Townsville, Queensland, Australia
- AIMS@JCU, Townsville, Queensland, Australia
| | - David G Bourne
- College of Science and Engineering, James Cook University, Townsville, Queensland, Australia
- Australian Institute of Marine Science, Townsville, Queensland, Australia
| | - Hugo B Harrison
- College of Science and Engineering, James Cook University, Townsville, Queensland, Australia
- Australian Institute of Marine Science, Townsville, Queensland, Australia
- AIMS@JCU, Townsville, Queensland, Australia
- School of Biological Sciences, University of Bristol, Bristol, UK
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2
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Potekhin A, Plotnikov AO, Gogoleva N, Sonntag B. Editorial: Microbial associations formed and hosted by protists, algae, and fungi. Front Microbiol 2024; 14:1341058. [PMID: 38249461 PMCID: PMC10799554 DOI: 10.3389/fmicb.2023.1341058] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2023] [Accepted: 12/08/2023] [Indexed: 01/23/2024] Open
Affiliation(s)
- Alexey Potekhin
- Research Department for Limnology, Mondsee, University of Innsbruck, Mondsee, Austria
| | - Andrey O. Plotnikov
- Institute for Cellular and Intracellular Symbiosis of the UrB RAS, Orenburg Federal Research Center, Orenburg, Russia
| | - Natalia Gogoleva
- Research Department for Limnology, Mondsee, University of Innsbruck, Mondsee, Austria
- Laboratory of Environmental Metagenomics, Institute of Fundamental Medicine and Biology, Kazan Federal University, Kazan, Russia
| | - Bettina Sonntag
- Research Department for Limnology, Mondsee, University of Innsbruck, Mondsee, Austria
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3
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Johnston EC, Cunning R, Burgess SC. Cophylogeny and specificity between cryptic coral species (Pocillopora spp.) at Mo'orea and their symbionts (Symbiodiniaceae). Mol Ecol 2022; 31:5368-5385. [PMID: 35960256 PMCID: PMC9805206 DOI: 10.1111/mec.16654] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2022] [Revised: 06/30/2022] [Accepted: 08/08/2022] [Indexed: 01/09/2023]
Abstract
The congruence between phylogenies of tightly associated groups of organisms (cophylogeny) reflects evolutionary links between ecologically important interactions. However, despite being a classic example of an obligate symbiosis, tests of cophylogeny between scleractinian corals and their photosynthetic algal symbionts have been hampered in the past because both corals and algae contain genetically unresolved and morphologically cryptic species. Here, we studied co-occurring, cryptic Pocillopora species from Mo'orea, French Polynesia, that differ in their relative abundance across depth. We constructed new phylogenies of the host Pocillopora (using complete mitochondrial genomes, genomic loci, and thousands of single nucleotide polymorphisms) and their Symbiodiniaceae symbionts (using ITS2 and psbAncr markers) and tested for cophylogeny. The analysis supported the presence of five Pocillopora species on the fore reef at Mo'orea that mostly hosted either Cladocopium latusorum or C. pacificum. Only Pocillopora species hosting C. latusorum also hosted taxa from Symbiodinium and Durusdinium. In general, the Cladocopium phylogeny mirrored the Pocillopora phylogeny. Within Cladocopium species, lineages also differed in their associations with Pocillopora haplotypes, except those showing evidence of nuclear introgression, and with depth in the two most common Pocillopora species. We also found evidence for a new Pocillopora species (haplotype 10), that has so far only been sampled from French Polynesia, that warrants formal identification. The linked phylogenies of these Pocillopora and Cladocopium species and lineages suggest that symbiont speciation is driven by niche diversification in the host, but there is still evidence for symbiont flexibility in some cases.
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Affiliation(s)
- Erika C. Johnston
- Department of Biological ScienceFlorida State UniversityTallahasseeFloridaUSA
| | - Ross Cunning
- Daniel P. Haerther Center for Conservation and ResearchJohn G. Shedd AquariumChicagoIllinoisUSA
| | - Scott C. Burgess
- Department of Biological ScienceFlorida State UniversityTallahasseeFloridaUSA
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4
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Rotterová J, Edgcomb VP, Čepička I, Beinart R. Anaerobic Ciliates as a Model Group for Studying Symbioses in Oxygen-depleted Environments. J Eukaryot Microbiol 2022; 69:e12912. [PMID: 35325496 DOI: 10.1111/jeu.12912] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Anaerobiosis has independently evolved in multiple lineages of ciliates, allowing them to colonize a variety of anoxic and oxygen-depleted habitats. Anaerobic ciliates commonly form symbiotic relationships with various prokaryotes, including methanogenic archaea and members of several bacterial groups. The hypothesized functions of these ecto- and endosymbionts include the symbiont utilizing the ciliate's fermentative end-products to increase host's anaerobic metabolic efficiency, or the symbiont directly providing the host with energy by denitrification or photosynthesis. The host, in turn, may protect the symbiont from competition, the environment, and predation. Despite rapid advances in sampling, molecular, and microscopy methods, as well as the associated broadening of the known diversity of anaerobic ciliates, many aspects of these ciliate symbioses, including host-specificity and co-evolution, remain largely unexplored. Nevertheless, with the number of comparative genomic and transcriptomic analyses targeting anaerobic ciliates and their symbionts on the rise, insights into the nature of these symbioses and the evolution of the ciliate transition to obligate anaerobiosis continue to deepen. This review summarizes the current body of knowledge regarding the complex nature of symbioses in anaerobic ciliates, the diversity of these symbionts, their role in the evolution of ciliate anaerobiosis and their significance in ecosystem-level processes.
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Affiliation(s)
- Johana Rotterová
- Graduate School of Oceanography, University of Rhode Island, Narragansett, Rhode Island, USA.,Department of Zoology, Faculty of Science, Charles University, Prague, Czech Republic
| | - Virginia P Edgcomb
- Department of Geology and Geophysics, Woods Hole Oceanographic Institution, Woods Hole, Massachusetts, USA
| | - Ivan Čepička
- Department of Zoology, Faculty of Science, Charles University, Prague, Czech Republic
| | - Roxanne Beinart
- Graduate School of Oceanography, University of Rhode Island, Narragansett, Rhode Island, USA
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5
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Suter EA, Pachiadaki M, Taylor GT, Edgcomb VP. Eukaryotic Parasites Are Integral to a Productive Microbial Food Web in Oxygen-Depleted Waters. Front Microbiol 2022; 12:764605. [PMID: 35069470 PMCID: PMC8770914 DOI: 10.3389/fmicb.2021.764605] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2021] [Accepted: 12/13/2021] [Indexed: 01/04/2023] Open
Abstract
Oxygen-depleted water columns (ODWCs) host a diverse community of eukaryotic protists that change dramatically in composition over the oxic-anoxic gradient. In the permanently anoxic Cariaco Basin, peaks in eukaryotic diversity occurred in layers where dark microbial activity (chemoautotrophy and heterotrophy) were highest, suggesting a link between prokaryotic activity and trophic associations with protists. Using 18S rRNA gene sequencing, parasites and especially the obligate parasitic clade, Syndiniales, appear to be particularly abundant, suggesting parasitism is an important, but overlooked interaction in ODWC food webs. Syndiniales were also associated with certain prokaryotic groups that are often found in ODWCs, including Marinimicrobia and Marine Group II archaea, evocative of feedbacks between parasitic infection events, release of organic matter, and prokaryotic assimilative activity. In a network analysis that included all three domains of life, bacterial and archaeal taxa were putative bottleneck and hub species, while a large proportion of edges were connected to eukaryotic nodes. Inclusion of parasites resulted in a more complex network with longer path lengths between members. Together, these results suggest that protists, and especially protistan parasites, play an important role in maintaining microbial food web complexity, particularly in ODWCs, where protist diversity and microbial productivity are high, but energy resources are limited relative to euphotic waters.
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Affiliation(s)
- Elizabeth A Suter
- Biology, Chemistry & Environmental Studies Department, Center for Environmental Research and Coastal Oceans Monitoring, Molloy College, Rockville Centre, NY, United States.,School of Marine and Atmospheric Sciences, Stony Brook University, Stony Brook, NY, United States
| | - Maria Pachiadaki
- Department of Biology, Woods Hole Oceanographic Institution, Woods Hole, MA, United States
| | - Gordon T Taylor
- School of Marine and Atmospheric Sciences, Stony Brook University, Stony Brook, NY, United States
| | - Virginia P Edgcomb
- Department of Geology & Geophysics, Woods Hole Oceanographic Institution, Woods Hole, MA, United States
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6
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Fokin SI, Serra V. Bacterial Symbiosis in Ciliates (Alveolata, Ciliophora): Roads Traveled and Those Still to be Taken. J Eukaryot Microbiol 2022; 69:e12886. [PMID: 35006645 PMCID: PMC9539572 DOI: 10.1111/jeu.12886] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2021] [Revised: 01/05/2022] [Accepted: 01/06/2022] [Indexed: 11/30/2022]
Abstract
The diversity of prokaryotic symbionts in Ciliophora and other protists is fascinatingly rich; they may even include some potentially pathogenic bacteria. In this review, we summarize currently available data on biodiversity and some morphological and biological peculiarities of prokaryotic symbionts mainly within the genera Paramecium and Euplotes. Another direction of ciliate symbiology, neglected for a long time and now re‐discovered, is the study of epibionts of ciliates. This promises a variety of interesting outcomes. Last, but not least, we stress the new technologies, such as next generation sequencing and the use of genomics data, which all can clarify many new aspects of relevance. For this reason, a brief overview of achievements in genomic studies on ciliate's symbionts is provided. Summing up the results of numerous scientific contributions, we systematically update current knowledge and outline the prospects as to how symbiology of Ciliophora may develop in the near future.
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Affiliation(s)
- Sergei I Fokin
- University of Pisa, Pisa, Italy.,St. Petersburg State University, St. Petersburg, Russia
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7
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Sogin EM, Kleiner M, Borowski C, Gruber-Vodicka HR, Dubilier N. Life in the Dark: Phylogenetic and Physiological Diversity of Chemosynthetic Symbioses. Annu Rev Microbiol 2021; 75:695-718. [PMID: 34351792 DOI: 10.1146/annurev-micro-051021-123130] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Possibly the last discovery of a previously unknown major ecosystem on Earth was made just over half a century ago, when researchers found teaming communities of animals flourishing two and a half kilometers below the ocean surface at hydrothermal vents. We now know that these highly productive ecosystems are based on nutritional symbioses between chemosynthetic bacteria and eukaryotes and that these chemosymbioses are ubiquitous in both deep-sea and shallow-water environments. The symbionts are primary producers that gain energy from the oxidation of reduced compounds, such as sulfide and methane, to fix carbon dioxide or methane into biomass to feed their hosts. This review outlines how the symbiotic partners have adapted to living together. We first focus on the phylogenetic and metabolic diversity of these symbioses and then highlight selected research directions that could advance our understanding of the processes that shaped the evolutionary and ecological success of these associations. Expected final online publication date for the Annual Review of Microbiology, Volume 75 is October 2021. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.
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Affiliation(s)
- E Maggie Sogin
- Max Planck Institute for Marine Microbiology, 28359, Bremen, Germany; ,
| | - Manuel Kleiner
- Department of Plant and Microbial Biology, North Carolina State University, Raleigh, North Carolina 27607, USA
| | - Christian Borowski
- Max Planck Institute for Marine Microbiology, 28359, Bremen, Germany; , .,MARUM-Center for Marine Environmental Sciences, University of Bremen, 28359, Bremen, Germany
| | | | - Nicole Dubilier
- Max Planck Institute for Marine Microbiology, 28359, Bremen, Germany; , .,MARUM-Center for Marine Environmental Sciences, University of Bremen, 28359, Bremen, Germany
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8
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Langdon A, Schwartz DJ, Bulow C, Sun X, Hink T, Reske KA, Jones C, Burnham CAD, Dubberke ER, Dantas G. Microbiota restoration reduces antibiotic-resistant bacteria gut colonization in patients with recurrent Clostridioides difficile infection from the open-label PUNCH CD study. Genome Med 2021; 13:28. [PMID: 33593430 PMCID: PMC7888090 DOI: 10.1186/s13073-021-00843-9] [Citation(s) in RCA: 40] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2020] [Accepted: 02/03/2021] [Indexed: 12/16/2022] Open
Abstract
BACKGROUND Once antibiotic-resistant bacteria become established within the gut microbiota, they can cause infections in the host and be transmitted to other people and the environment. Currently, there are no effective modalities for decreasing or preventing colonization by antibiotic-resistant bacteria. Intestinal microbiota restoration can prevent Clostridioides difficile infection (CDI) recurrences. Another potential application of microbiota restoration is suppression of non-C. difficile multidrug-resistant bacteria and overall decrease in the abundance of antibiotic resistance genes (the resistome) within the gut microbiota. This study characterizes the effects of RBX2660, a microbiota-based investigational therapeutic, on the composition and abundance of the gut microbiota and resistome, as well as multidrug-resistant organism carriage, after delivery to patients suffering from recurrent CDI. METHODS An open-label, multi-center clinical trial in 11 centers in the USA for the safety and efficacy of RBX2660 on recurrent CDI was conducted. Fecal specimens from 29 of these subjects with recurrent CDI who received either one (N = 16) or two doses of RBX2660 (N = 13) were analyzed secondarily. Stool samples were collected prior to and at intervals up to 6 months post-therapy and analyzed in three ways: (1) 16S rRNA gene sequencing for microbiota taxonomic composition, (2) whole metagenome shotgun sequencing for functional pathways and antibiotic resistome content, and (3) selective and differential bacterial culturing followed by isolate genome sequencing to longitudinally track multidrug-resistant organisms. RESULTS Successful prevention of CDI recurrence with RBX2660 correlated with taxonomic convergence of patient microbiota to the donor microbiota as measured by weighted UniFrac distance. RBX2660 dramatically reduced the abundance of antibiotic-resistant Enterobacteriaceae in the 2 months after administration. Fecal antibiotic resistance gene carriage decreased in direct relationship to the degree to which donor microbiota engrafted. CONCLUSIONS Microbiota-based therapeutics reduce resistance gene abundance and resistant organisms in the recipient gut microbiome. This approach could potentially reduce the risk of infections caused by resistant organisms within the patient and the transfer of resistance genes or pathogens to others. TRIAL REGISTRATION ClinicalTrials.gov, NCT01925417 ; registered on August 19, 2013.
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Affiliation(s)
- Amy Langdon
- The Edison Family Center for Genome Sciences & Systems Biology, Washington University School of Medicine in St. Louis, St. Louis, MO USA
- Clinical Research Training Center, Washington University School of Medicine in St. Louis, St. Louis, MO USA
| | - Drew J. Schwartz
- The Edison Family Center for Genome Sciences & Systems Biology, Washington University School of Medicine in St. Louis, St. Louis, MO USA
- Department of Pediatrics, Washington University School of Medicine in St. Louis, St. Louis, MO USA
| | - Christopher Bulow
- The Edison Family Center for Genome Sciences & Systems Biology, Washington University School of Medicine in St. Louis, St. Louis, MO USA
| | - Xiaoqing Sun
- The Edison Family Center for Genome Sciences & Systems Biology, Washington University School of Medicine in St. Louis, St. Louis, MO USA
- Department of Pathology and Immunology, Division of Laboratory and Genomic Medicine, Washington University School of Medicine in St. Louis, St. Louis, MO 63110 USA
| | - Tiffany Hink
- Department of Medicine, Washington University School of Medicine in St. Louis, St. Louis, MO 63110 USA
| | - Kimberly A. Reske
- Department of Medicine, Washington University School of Medicine in St. Louis, St. Louis, MO 63110 USA
| | | | - Carey-Ann D. Burnham
- Department of Pediatrics, Washington University School of Medicine in St. Louis, St. Louis, MO USA
- Department of Pathology and Immunology, Division of Laboratory and Genomic Medicine, Washington University School of Medicine in St. Louis, St. Louis, MO 63110 USA
- Department of Medicine, Washington University School of Medicine in St. Louis, St. Louis, MO 63110 USA
- Department of Molecular Microbiology, Washington University School of Medicine in St. Louis, St. Louis, MO 63110 USA
| | - Erik R. Dubberke
- Department of Medicine, Washington University School of Medicine in St. Louis, St. Louis, MO 63110 USA
| | - Gautam Dantas
- The Edison Family Center for Genome Sciences & Systems Biology, Washington University School of Medicine in St. Louis, St. Louis, MO USA
- Department of Pathology and Immunology, Division of Laboratory and Genomic Medicine, Washington University School of Medicine in St. Louis, St. Louis, MO 63110 USA
- Department of Molecular Microbiology, Washington University School of Medicine in St. Louis, St. Louis, MO 63110 USA
- Department of Biomedical Engineering, Washington University in St Louis, St. Louis, MO USA
| | - for the CDC Prevention Epicenter Program
- The Edison Family Center for Genome Sciences & Systems Biology, Washington University School of Medicine in St. Louis, St. Louis, MO USA
- Clinical Research Training Center, Washington University School of Medicine in St. Louis, St. Louis, MO USA
- Department of Pediatrics, Washington University School of Medicine in St. Louis, St. Louis, MO USA
- Department of Pathology and Immunology, Division of Laboratory and Genomic Medicine, Washington University School of Medicine in St. Louis, St. Louis, MO 63110 USA
- Department of Medicine, Washington University School of Medicine in St. Louis, St. Louis, MO 63110 USA
- Rebiotix, Inc., Minneapolis, MN USA
- Department of Molecular Microbiology, Washington University School of Medicine in St. Louis, St. Louis, MO 63110 USA
- Department of Biomedical Engineering, Washington University in St Louis, St. Louis, MO USA
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9
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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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10
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Bright M, Espada-Hinojosa S, Volland JM, Drexel J, Kesting J, Kolar I, Morchner D, Nussbaumer A, Ott J, Scharhauser F, Schuster L, Zambalos HC, Nemeschkal HL. Thiotrophic bacterial symbiont induces polyphenism in giant ciliate host Zoothamnium niveum. Sci Rep 2019; 9:15081. [PMID: 31636334 PMCID: PMC6803713 DOI: 10.1038/s41598-019-51511-3] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2019] [Accepted: 10/02/2019] [Indexed: 11/09/2022] Open
Abstract
Evolutionary theory predicts potential shifts between cooperative and uncooperative behaviour under fluctuating environmental conditions. This leads to unstable benefits to the partners and restricts the evolution of dependence. High dependence is usually found in those hosts in which vertically transmitted symbionts provide nutrients reliably. Here we study host dependence in the marine, giant colonial ciliate Zoothamnium niveum and its vertically transmitted, nutritional, thiotrophic symbiont from an unstable environment of degrading wood. Previously, we have shown that sulphidic conditions lead to high host fitness and oxic conditions to low fitness, but the fate of the symbiont has not been studied. We combine several experimental approaches to provide evidence for a sulphide-tolerant host with striking polyphenism involving two discrete morphs, a symbiotic and an aposymbiotic one. The two differ significantly in colony growth form and fitness. This polyphenism is triggered by chemical conditions and elicited by the symbiont’s presence on the dispersing swarmer. We provide evidence of a single aposymbiotic morph found in nature. We propose that despite a high fitness loss when aposymbiotic, the ciliate has retained a facultative life style and may use the option to live without its symbiont to overcome spatial and temporal shortage of sulphide in nature.
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Affiliation(s)
- Monika Bright
- University of Vienna, Department of Limnology and Bio-Oceanography, Vienna, Austria.
| | | | - Jean-Marie Volland
- University of Vienna, Department of Limnology and Bio-Oceanography, Vienna, Austria
| | - Judith Drexel
- University of Vienna, Department of Limnology and Bio-Oceanography, Vienna, Austria
| | - Julia Kesting
- University of Vienna, Department of Limnology and Bio-Oceanography, Vienna, Austria
| | - Ingrid Kolar
- University of Vienna, Department of Limnology and Bio-Oceanography, Vienna, Austria
| | - Denny Morchner
- University of Vienna, Department of Limnology and Bio-Oceanography, Vienna, Austria
| | - Andrea Nussbaumer
- University of Vienna, Department of Limnology and Bio-Oceanography, Vienna, Austria
| | - Jörg Ott
- University of Vienna, Department of Limnology and Bio-Oceanography, Vienna, Austria
| | - Florian Scharhauser
- University of Vienna, Department of Limnology and Bio-Oceanography, Vienna, Austria
| | - Lukas Schuster
- University of Vienna, Department of Limnology and Bio-Oceanography, Vienna, Austria
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11
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Enrichment of intracellular sulphur cycle -associated bacteria in intertidal benthic foraminifera revealed by 16S and aprA gene analysis. Sci Rep 2019; 9:11692. [PMID: 31406214 PMCID: PMC6690927 DOI: 10.1038/s41598-019-48166-5] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2019] [Accepted: 07/30/2019] [Indexed: 12/21/2022] Open
Abstract
Benthic foraminifera are known to play an important role in marine carbon and nitrogen cycles. Here, we report an enrichment of sulphur cycle -associated bacteria inside intertidal benthic foraminifera (Ammonia sp. (T6), Haynesina sp. (S16) and Elphidium sp. (S5)), using a metabarcoding approach targeting the 16S rRNA and aprA -genes. The most abundant intracellular bacterial groups included the genus Sulfurovum and the order Desulfobacterales. The bacterial 16S OTUs are likely to originate from the sediment bacterial communities, as the taxa found inside the foraminifera were also present in the sediment. The fact that 16S rRNA and aprA -gene derived intracellular bacterial OTUs were species-specific and significantly different from the ambient sediment community implies that bacterivory is an unlikely scenario, as benthic foraminifera are known to digest bacteria only randomly. Furthermore, these foraminiferal species are known to prefer other food sources than bacteria. The detection of sulphur-cycle related bacterial genes in this study suggests a putative role for these bacteria in the metabolism of the foraminiferal host. Future investigation into environmental conditions under which transcription of S-cycle genes are activated would enable assessment of their role and the potential foraminiferal/endobiont contribution to the sulphur-cycle.
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12
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Boscaro V, Husnik F, Vannini C, Keeling PJ. Symbionts of the ciliate Euplotes: diversity, patterns and potential as models for bacteria-eukaryote endosymbioses. Proc Biol Sci 2019; 286:20190693. [PMID: 31311477 DOI: 10.1098/rspb.2019.0693] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
Endosymbioses between bacteria and eukaryotes are enormously important in ecology and evolution, and as such are intensely studied. Despite this, the range of investigated hosts is narrow in the context of the whole eukaryotic tree of life: most of the information pertains to animal hosts, while most of the diversity is found in unicellular protists. A prominent case study is the ciliate Euplotes, which has repeatedly taken up the bacterium Polynucleobacter from the environment, triggering its transformation into obligate endosymbiont. This multiple origin makes the relationship an excellent model to understand recent symbioses, but Euplotes may host bacteria other than Polynucleobacter, and a more detailed knowledge of these additional interactions is needed in order to correctly interpret the system. Here, we present the first systematic survey of Euplotes endosymbionts, adopting a classical as well as a metagenomic approach, and review the state of knowledge. The emerging picture is indeed quite complex, with some Euplotes harbouring rich, stable prokaryotic communities not unlike those of multicellular animals. We provide insights into the distribution, evolution and diversity of these symbionts (including the establishment of six novel bacterial taxa), and outline differences and similarities with the most well-understood group of eukaryotic hosts: insects.
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Affiliation(s)
- Vittorio Boscaro
- Department of Botany, University of British Columbia, British Columbia, Canada
| | - Filip Husnik
- Department of Botany, University of British Columbia, British Columbia, Canada
| | | | - Patrick J Keeling
- Department of Botany, University of British Columbia, British Columbia, Canada
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13
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Rossi A, Bellone A, Fokin SI, Boscaro V, Vannini C. Detecting Associations Between Ciliated Protists and Prokaryotes with Culture-Independent Single-Cell Microbiomics: a Proof-of-Concept Study. MICROBIAL ECOLOGY 2019; 78:232-242. [PMID: 30411190 DOI: 10.1007/s00248-018-1279-9] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/16/2018] [Accepted: 10/22/2018] [Indexed: 06/08/2023]
Abstract
Symbioses between prokaryotes and microbial eukaryotes, particularly ciliated protists, have been studied for a long time. Nevertheless, researchers have focused only on a few host genera and species, mainly due to difficulties in cultivating the hosts, and usually have considered a single symbiont at a time. Here, we present a pilot study using a single-cell microbiomic approach to circumvent these issues. Unicellular ciliate isolation followed by simultaneous amplification of eukaryotic and prokaryotic markers was used. Our preliminary test gave reliable and satisfactory results both on samples collected from different habitats (marine and freshwater) and on ciliates belonging to different taxonomic groups. Results suggest that, as already assessed for many macro-organisms like plants and metazoans, ciliated protists harbor distinct microbiomes. The applied approach detected new potential symbionts as well as new hosts for previously described ones, with relatively low time and cost effort and without culturing. When further developed, single-cell microbiomics for ciliates could be applied to a large number of studies aiming to unravel the evolutionary and ecological meaning of these symbiotic systems.
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Affiliation(s)
- Alessia Rossi
- Department of Biology, University of Pisa, Pisa, Italy
| | | | - Sergei I Fokin
- Department of Biology, University of Pisa, Pisa, Italy
- Department of Invertebrate Zoology, St.-Petersburg State University, St. Petersburg, Russia
- St. Petersburg Branch of the S.I. Vavilov Institute of History of Science and Technology, Russian Academy of Sciences, St. Petersburg, Russia
| | - Vittorio Boscaro
- Department of Biology, University of Pisa, Pisa, Italy
- Department of Botany, University of British Columbia, Vancouver, Canada
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14
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Seah BKB, Antony CP, Huettel B, Zarzycki J, Schada von Borzyskowski L, Erb TJ, Kouris A, Kleiner M, Liebeke M, Dubilier N, Gruber-Vodicka HR. Sulfur-Oxidizing Symbionts without Canonical Genes for Autotrophic CO 2 Fixation. mBio 2019; 10:e01112-19. [PMID: 31239380 PMCID: PMC6593406 DOI: 10.1128/mbio.01112-19] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2019] [Accepted: 05/23/2019] [Indexed: 01/25/2023] Open
Abstract
Since the discovery of symbioses between sulfur-oxidizing (thiotrophic) bacteria and invertebrates at hydrothermal vents over 40 years ago, it has been assumed that autotrophic fixation of CO2 by the symbionts drives these nutritional associations. In this study, we investigated "Candidatus Kentron," the clade of symbionts hosted by Kentrophoros, a diverse genus of ciliates which are found in marine coastal sediments around the world. Despite being the main food source for their hosts, Kentron bacteria lack the key canonical genes for any of the known pathways for autotrophic carbon fixation and have a carbon stable isotope fingerprint that is unlike other thiotrophic symbionts from similar habitats. Our genomic and transcriptomic analyses instead found metabolic features consistent with growth on organic carbon, especially organic and amino acids, for which they have abundant uptake transporters. All known thiotrophic symbionts have converged on using reduced sulfur to gain energy lithotrophically, but they are diverse in their carbon sources. Some clades are obligate autotrophs, while many are mixotrophs that can supplement autotrophic carbon fixation with heterotrophic capabilities similar to those in Kentron. Here we show that Kentron bacteria are the only thiotrophic symbionts that appear to be entirely heterotrophic, unlike all other thiotrophic symbionts studied to date, which possess either the Calvin-Benson-Bassham or the reverse tricarboxylic acid cycle for autotrophy.IMPORTANCE Many animals and protists depend on symbiotic sulfur-oxidizing bacteria as their main food source. These bacteria use energy from oxidizing inorganic sulfur compounds to make biomass autotrophically from CO2, serving as primary producers for their hosts. Here we describe a clade of nonautotrophic sulfur-oxidizing symbionts, "Candidatus Kentron," associated with marine ciliates. They lack genes for known autotrophic pathways and have a carbon stable isotope fingerprint heavier than other symbionts from similar habitats. Instead, they have the potential to oxidize sulfur to fuel the uptake of organic compounds for heterotrophic growth, a metabolic mode called chemolithoheterotrophy that is not found in other symbioses. Although several symbionts have heterotrophic features to supplement primary production, in Kentron they appear to supplant it entirely.
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Affiliation(s)
| | | | - Bruno Huettel
- Max Planck Genome Centre Cologne, Max Planck Institute for Plant Breeding Research, Cologne, Germany
| | - Jan Zarzycki
- Max Planck Institute for Terrestrial Microbiology, Marburg, Germany
| | | | - Tobias J Erb
- Max Planck Institute for Terrestrial Microbiology, Marburg, Germany
| | - Angela Kouris
- Energy Bioengineering and Geomicrobiology Group, University of Calgary, Calgary, Alberta, Canada
| | - Manuel Kleiner
- Department of Plant and Microbial Biology, North Carolina State University, Raleigh, North Carolina, USA
| | - Manuel Liebeke
- Max Planck Institute for Marine Microbiology, Bremen, Germany
| | - Nicole Dubilier
- Max Planck Institute for Marine Microbiology, Bremen, Germany
- MARUM, Center for Marine Environmental Sciences, University of Bremen, Bremen, Germany
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15
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Chemosynthetic symbiont with a drastically reduced genome serves as primary energy storage in the marine flatworm Paracatenula. Proc Natl Acad Sci U S A 2019; 116:8505-8514. [PMID: 30962361 PMCID: PMC6486704 DOI: 10.1073/pnas.1818995116] [Citation(s) in RCA: 38] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
Animals typically store their primary energy reserves in specialized cells. Here, we show that in the small marine flatworm Paracatenula, this function is performed by its bacterial chemosynthetic symbiont. The intracellular symbiont occupies half of the biomass in the symbiosis and has a highly reduced genome but efficiently stocks up and maintains carbon and energy, particularly sugars. The host rarely digests the symbiont cells to access these stocks. Instead, the symbionts appear to provide the bulk nutrition by secreting outer-membrane vesicles. This is in contrast to all other described chemosynthetic symbioses, where the hosts continuously digest full cells of a small and ideally growing symbiont population that cannot provide a long-term buffering capacity during nutrient limitation. Hosts of chemoautotrophic bacteria typically have much higher biomass than their symbionts and consume symbiont cells for nutrition. In contrast to this, chemoautotrophic Candidatus Riegeria symbionts in mouthless Paracatenula flatworms comprise up to half of the biomass of the consortium. Each species of Paracatenula harbors a specific Ca. Riegeria, and the endosymbionts have been vertically transmitted for at least 500 million years. Such prolonged strict vertical transmission leads to streamlining of symbiont genomes, and the retained physiological capacities reveal the functions the symbionts provide to their hosts. Here, we studied a species of Paracatenula from Sant’Andrea, Elba, Italy, using genomics, gene expression, imaging analyses, as well as targeted and untargeted MS. We show that its symbiont, Ca. R. santandreae has a drastically smaller genome (1.34 Mb) than the symbiont´s free-living relatives (4.29–4.97 Mb) but retains a versatile and energy-efficient metabolism. It encodes and expresses a complete intermediary carbon metabolism and enhanced carbon fixation through anaplerosis and accumulates massive intracellular inclusions such as sulfur, polyhydroxyalkanoates, and carbohydrates. Compared with symbiotic and free-living chemoautotrophs, Ca. R. santandreae’s versatility in energy storage is unparalleled in chemoautotrophs with such compact genomes. Transmission EM as well as host and symbiont expression data suggest that Ca. R. santandreae largely provisions its host via outer-membrane vesicle secretion. With its high share of biomass in the symbiosis and large standing stocks of carbon and energy reserves, it has a unique role for bacterial symbionts—serving as the primary energy storage for its animal host.
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16
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Beinart R, Rotterová J, Čepička I, Gast R, Edgcomb V. The genome of an endosymbiotic methanogen is very similar to those of its free‐living relatives. Environ Microbiol 2018; 20:2538-2551. [DOI: 10.1111/1462-2920.14279] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Affiliation(s)
- R.A. Beinart
- Department of Geology and Geophysics Woods Hole Oceanographic Institution Woods Hole MA USA
- Department of Biology Woods Hole Oceanographic Institution Woods Hole MA USA
| | - J. Rotterová
- Department of Zoology Charles University Prague Czech Republic
| | - I. Čepička
- Department of Zoology Charles University Prague Czech Republic
| | - R.J. Gast
- Department of Biology Woods Hole Oceanographic Institution Woods Hole MA USA
| | - V.P. Edgcomb
- Department of Geology and Geophysics Woods Hole Oceanographic Institution Woods Hole MA USA
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17
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Volland JM, Schintlmeister A, Zambalos H, Reipert S, Mozetič P, Espada-Hinojosa S, Turk V, Wagner M, Bright M. NanoSIMS and tissue autoradiography reveal symbiont carbon fixation and organic carbon transfer to giant ciliate host. THE ISME JOURNAL 2018; 12:714-727. [PMID: 29426952 PMCID: PMC5854253 DOI: 10.1038/s41396-018-0069-1] [Citation(s) in RCA: 27] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/23/2017] [Revised: 10/03/2017] [Accepted: 10/09/2017] [Indexed: 11/09/2022]
Abstract
The giant colonial ciliate Zoothamnium niveum harbors a monolayer of the gammaproteobacteria Cand. Thiobios zoothamnicoli on its outer surface. Cultivation experiments revealed maximal growth and survival under steady flow of high oxygen and low sulfide concentrations. We aimed at directly demonstrating the sulfur-oxidizing, chemoautotrophic nature of the symbionts and at investigating putative carbon transfer from the symbiont to the ciliate host. We performed pulse-chase incubations with 14C- and 13C-labeled bicarbonate under varying environmental conditions. A combination of tissue autoradiography and nanoscale secondary ion mass spectrometry coupled with transmission electron microscopy was used to follow the fate of the radioactive and stable isotopes of carbon, respectively. We show that symbiont cells fix substantial amounts of inorganic carbon in the presence of sulfide, but also (to a lesser degree) in the absence of sulfide by utilizing internally stored sulfur. Isotope labeling patterns point to translocation of organic carbon to the host through both release of these compounds and digestion of symbiont cells. The latter mechanism is also supported by ultracytochemical detection of acid phosphatase in lysosomes and in food vacuoles of ciliate cells. Fluorescence in situ hybridization of freshly collected ciliates revealed that the vast majority of ingested microbial cells were ectosymbionts.
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Affiliation(s)
- Jean-Marie Volland
- Department of Limnology and Bio-Oceanography, University of Vienna, Vienna, Austria.
| | - Arno Schintlmeister
- Department of Microbiology and Ecosystem Science, Research Network "Chemistry meets Microbiology" and Large-Instrument Facility for Advanced Isotope Research, University of Vienna, Vienna, Austria
| | - Helena Zambalos
- Department of Limnology and Bio-Oceanography, University of Vienna, Vienna, Austria
| | - Siegfried Reipert
- Cell Imaging and Ultrastructure Research (CIUS), University of Vienna, Vienna, Austria
| | - Patricija Mozetič
- National Institute of Biology, Marine Biology Station, Piran, Slovenia
| | | | - Valentina Turk
- National Institute of Biology, Marine Biology Station, Piran, Slovenia
| | - Michael Wagner
- Department of Microbiology and Ecosystem Science, Research Network "Chemistry meets Microbiology" and Large-Instrument Facility for Advanced Isotope Research, University of Vienna, Vienna, Austria
| | - Monika Bright
- Department of Limnology and Bio-Oceanography, University of Vienna, Vienna, Austria
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18
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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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