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Maciejowski WJ, Gile GH, Jerlström-Hultqvist J, Dacks JB. Ancient and pervasive expansion of adaptin-related vesicle coat machinery across Parabasalia. Int J Parasitol 2023; 53:233-245. [PMID: 36898426 DOI: 10.1016/j.ijpara.2023.01.002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2022] [Revised: 01/30/2023] [Accepted: 01/30/2023] [Indexed: 03/11/2023]
Abstract
The eukaryotic phylum Parabasalia is composed primarily of anaerobic, endobiotic organisms such as the veterinary parasite Tritrichomonas foetus and the human parasite Trichomonas vaginalis, the latter causing the most prevalent, non-viral, sexually transmitted disease world-wide. Although a parasitic lifestyle is generally associated with a reduction in cell biology, T. vaginalis provides a striking counter-example. The 2007 T. vaginalis genome paper reported a massive and selective expansion of encoded proteins involved in vesicle trafficking, particularly those implicated in the late secretory and endocytic systems. Chief amongst these were the hetero-tetrameric adaptor proteins or 'adaptins', with T. vaginalis encoding ∼3.5 times more such proteins than do humans. The provenance of such a complement, and how it relates to the transition from a free-living or endobiotic state to parasitism, remains unclear. In this study, we performed a comprehensive bioinformatic and molecular evolutionary investigation of the heterotetrameric cargo adaptor-derived coats, comparing the molecular complement and evolution of these proteins between T. vaginalis, T. foetus and the available diversity of endobiotic parabasalids. Notably, with the recent discovery of Anaeramoeba spp. as the free-living sister lineage to all parabasalids, we were able to delve back to time points earlier in the lineage's history than ever before. We found that, although T. vaginalis still encodes the most HTAC subunits amongst parabasalids, the duplications giving rise to the complement took place more deeply and at various stages across the lineage. While some duplications appear to have convergently shaped the parasitic lineages, the largest jump is in the transition from free-living to endobiotic lifestyle with both gains and losses shaping the encoded complement. This work details the evolution of a cellular system across an important lineage of parasites and provides insight into the evolutionary dynamics of an example of expansion of protein machinery, counter to the more common trends observed in many parasitic systems.
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Affiliation(s)
- William J Maciejowski
- Division of Infectious Diseases, Department of Medicine, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, Canada; Department of Biological Sciences, University of Alberta, Edmonton, Canada; Women and Children's Health Research Institute, University of Alberta, Edmonton, Canada
| | - Gillian H Gile
- School of Life Sciences, Arizona State University, 427 E Tyler Mall, Tempe, Arizona, USA
| | - Jon Jerlström-Hultqvist
- Department of Cell and Molecular Biology, BMC, Box 586, Uppsala Universitet, SE-751 24 Uppsala, Sweden. https://twitter.com/jon_hultqvist
| | - Joel B Dacks
- Division of Infectious Diseases, Department of Medicine, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, Canada; Department of Biological Sciences, University of Alberta, Edmonton, Canada; Women and Children's Health Research Institute, University of Alberta, Edmonton, Canada; Institute of Parasitology, Biology Centre, Czech Academy of Sciences, České Budějovice (Budweis), Czech Republic.
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2
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Céza V, Kotyk M, Kubánková A, Yubuki N, Šťáhlavský F, Silberman JD, Čepička I. Free-living Trichomonads are Unexpectedly Diverse. Protist 2022; 173:125883. [DOI: 10.1016/j.protis.2022.125883] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2021] [Revised: 04/22/2022] [Accepted: 04/28/2022] [Indexed: 10/18/2022]
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3
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Evolution of the microtubular cytoskeleton (flagellar apparatus) in parasitic protists. Mol Biochem Parasitol 2016; 209:26-34. [DOI: 10.1016/j.molbiopara.2016.02.002] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2015] [Revised: 02/02/2016] [Accepted: 02/05/2016] [Indexed: 01/16/2023]
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4
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Xu F, Jerlström-Hultqvist J, Kolisko M, Simpson AGB, Roger AJ, Svärd SG, Andersson JO. On the reversibility of parasitism: adaptation to a free-living lifestyle via gene acquisitions in the diplomonad Trepomonas sp. PC1. BMC Biol 2016; 14:62. [PMID: 27480115 PMCID: PMC4967989 DOI: 10.1186/s12915-016-0284-z] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2016] [Accepted: 07/13/2016] [Indexed: 01/08/2023] Open
Abstract
Background It is generally thought that the evolutionary transition to parasitism is irreversible because it is associated with the loss of functions needed for a free-living lifestyle. Nevertheless, free-living taxa are sometimes nested within parasite clades in phylogenetic trees, which could indicate that they are secondarily free-living. Herein, we test this hypothesis by studying the genomic basis for evolutionary transitions between lifestyles in diplomonads, a group of anaerobic eukaryotes. Most described diplomonads are intestinal parasites or commensals of various animals, but there are also free-living diplomonads found in oxygen-poor environments such as marine and freshwater sediments. All these nest well within groups of parasitic diplomonads in phylogenetic trees, suggesting that they could be secondarily free-living. Results We present a transcriptome study of Trepomonas sp. PC1, a diplomonad isolated from marine sediment. Analysis of the metabolic genes revealed a number of proteins involved in degradation of the bacterial membrane and cell wall, as well as an extended set of enzymes involved in carbohydrate degradation and nucleotide metabolism. Phylogenetic analyses showed that most of the differences in metabolic capacity between free-living Trepomonas and the parasitic diplomonads are due to recent acquisitions of bacterial genes via gene transfer. Interestingly, one of the acquired genes encodes a ribonucleotide reductase, which frees Trepomonas from the need to scavenge deoxyribonucleosides. The transcriptome included a gene encoding squalene-tetrahymanol cyclase. This enzyme synthesizes the sterol substitute tetrahymanol in the absence of oxygen, potentially allowing Trepomonas to thrive under anaerobic conditions as a free-living bacterivore, without depending on sterols from other eukaryotes. Conclusions Our findings are consistent with the phylogenetic evidence that the last common ancestor of diplomonads was dependent on a host and that Trepomonas has adapted secondarily to a free-living lifestyle. We believe that similar studies of other groups where free-living taxa are nested within parasites could reveal more examples of secondarily free-living eukaryotes. Electronic supplementary material The online version of this article (doi:10.1186/s12915-016-0284-z) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Feifei Xu
- Department of Cell and Molecular Biology, Science for Life Laboratory, Uppsala University, Uppsala, Sweden
| | - Jon Jerlström-Hultqvist
- Department of Cell and Molecular Biology, Science for Life Laboratory, Uppsala University, Uppsala, Sweden.,Present address: Department of Medical Biochemistry and Microbiology, Uppsala University, Uppsala, Sweden
| | - Martin Kolisko
- Department of Biology, Dalhousie University, Halifax, NS, Canada.,Department of Biochemistry and Molecular Biology, Dalhousie University, Halifax, NS, Canada.,Present address: Botany Department, University of British Columbia, Vancouver, BC, Canada
| | - Alastair G B Simpson
- Department of Biology, Dalhousie University, Halifax, NS, Canada.,Canadian Institute for Advanced Research, Integrated Microbial Biodiversity Program, Toronto, ON, Canada
| | - Andrew J Roger
- Department of Biochemistry and Molecular Biology, Dalhousie University, Halifax, NS, Canada.,Canadian Institute for Advanced Research, Integrated Microbial Biodiversity Program, Toronto, ON, Canada
| | - Staffan G Svärd
- Department of Cell and Molecular Biology, Science for Life Laboratory, Uppsala University, Uppsala, Sweden
| | - Jan O Andersson
- Department of Cell and Molecular Biology, Science for Life Laboratory, Uppsala University, Uppsala, Sweden.
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Pánek T, Táborský P, Pachiadaki MG, Hroudová M, Vlček Č, Edgcomb VP, Čepička I. Combined Culture-Based and Culture-Independent Approaches Provide Insights into Diversity of Jakobids, an Extremely Plesiomorphic Eukaryotic Lineage. Front Microbiol 2015; 6:1288. [PMID: 26635756 PMCID: PMC4649034 DOI: 10.3389/fmicb.2015.01288] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2015] [Accepted: 11/03/2015] [Indexed: 11/13/2022] Open
Abstract
We used culture-based and culture-independent approaches to discover diversity and ecology of anaerobic jakobids (Excavata: Jakobida), an overlooked, deep-branching lineage of free-living nanoflagellates related to Euglenozoa. Jakobids are among a few lineages of nanoflagellates frequently detected in anoxic habitats by PCR-based studies, however only two strains of a single jakobid species have been isolated from those habitats. We recovered 712 environmental sequences and cultured 21 new isolates of anaerobic jakobids that collectively represent at least ten different species in total, from which four are uncultured. Two cultured species have never been detected by environmental, PCR-based methods. Surprisingly, culture-based and culture-independent approaches were able to reveal a relatively high proportion of overall species diversity of anaerobic jakobids—60 or 80%, respectively. Our phylogenetic analyses based on SSU rDNA and six protein-coding genes showed that anaerobic jakobids constitute a clade of morphologically similar, but genetically and ecologically diverse protists—Stygiellidae fam. nov. Our investigation combines culture-based and environmental molecular-based approaches to capture a wider extent of species diversity and shows Stygiellidae as a group that ordinarily inhabits anoxic, sulfide- and ammonium-rich marine habitats worldwide.
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Affiliation(s)
- Tomáš Pánek
- Department of Zoology, Faculty of Science, Charles University in Prague Prague, Czech Republic
| | - Petr Táborský
- Department of Zoology, Faculty of Science, Charles University in Prague Prague, Czech Republic
| | - Maria G Pachiadaki
- Geology and Geophysics Department, Woods Hole Oceanographic Institution Woods Hole, MA, USA
| | - Miluše Hroudová
- Department of Genomics and Bioinformatics, Institute of Molecular Genetics, Czech Academy of Sciences Prague, Czech Republic
| | - Čestmír Vlček
- Department of Genomics and Bioinformatics, Institute of Molecular Genetics, Czech Academy of Sciences Prague, Czech Republic
| | - Virginia P Edgcomb
- Geology and Geophysics Department, Woods Hole Oceanographic Institution Woods Hole, MA, USA
| | - Ivan Čepička
- Department of Zoology, Faculty of Science, Charles University in Prague Prague, Czech Republic
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Céza V, Pánek T, Smejkalová P, Čepička I. Molecular and morphological diversity of the genus Hypotrichomonas (Parabasalia: Hypotrichomonadida), with descriptions of six new species. Eur J Protistol 2015; 51:158-72. [PMID: 25855142 DOI: 10.1016/j.ejop.2015.02.003] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2014] [Revised: 02/09/2015] [Accepted: 02/09/2015] [Indexed: 11/30/2022]
Abstract
The genus HypotrichomonasLee, 1960 belongs to the small parabasalian class Hypotrichomonadea. Although five Hypotrichomonas species have been described from intestines of lizards and birds, some descriptions were brief and incomplete. Only the type species H. acosta has been observed repeatedly. We have established 23 strains of the genus Hypotrichomonas in culture. Phylogenetic and morphological analyses showed that these isolates represent eight distinct species, six of which are novel. Three of the species showed unusual morphology, such as a reduced undulating membrane, absence of the free part of the recurrent flagellum or a costa-like fiber. Our strains were isolated from a wide range of hosts including cockroaches, frogs, tortoises, lizards, snakes, marsupials, pigs, rodents, and primates. The genus Hypotrichomonas thus contains a relatively large number of species that differ in morphology, phylogenetic position and host range. It is remarkable that such diversity of hypotrichomonads was previously undetected, although a number of studies dealt with intestinal trichomonads of vertebrates and invertebrates. Our results indicate that the diversity of the genus Hypotrichomonas as well as of the whole Parabasalia is still only poorly understood, and the lineages described so far likely represent only a small fraction of the true diversity of parabasalids.
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Affiliation(s)
- Vít Céza
- Department of Zoology, Faculty of Science, Charles University in Prague, Vinicna 7, Prague 2, Czech Republic
| | - Tomáš Pánek
- Department of Zoology, Faculty of Science, Charles University in Prague, Vinicna 7, Prague 2, Czech Republic
| | - Pavla Smejkalová
- Department of Zoology, Faculty of Science, Charles University in Prague, Vinicna 7, Prague 2, Czech Republic; Department of Parasitology, Faculty of Science, Charles University in Prague, Vinicna 7, Prague 2, Czech Republic
| | - Ivan Čepička
- Department of Zoology, Faculty of Science, Charles University in Prague, Vinicna 7, Prague 2, Czech Republic.
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7
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Smejkalová P, Votýpka J, Lukeš J, Čepička I. First report on trichomonads from true bugs. Folia Parasitol (Praha) 2014. [DOI: 10.14411/fp.2014.025] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
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Martinez-Girón R, Cornelis van Woerden H. Lophomonas blattarum and bronchopulmonary disease. J Med Microbiol 2013; 62:1641-1648. [PMID: 23946475 DOI: 10.1099/jmm.0.059311-0] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
The natural habitat of the multiflagellate protozoon Lophomonas blattarum is as an endocommensal in the hindgut of insects such as cockroaches. However, it also causes bronchopulmonary disease in humans. The aim of this paper was to review the literature on this organism in the context of respiratory disease. The biology epidemiology, route of transmission, pathogenic mechanisms and diagnosis methods are also described. A total of 61 cases were identified in the literature. The majority of these reports were from China, with some cases from Peru and Spain. Most cases were adult males, although paediatric cases were reported in Peru. Clinical presentation was non-specific, including symptoms such as fever, cough and breathless. Antiprotozoal therapy was generally effective.
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Affiliation(s)
- Rafael Martinez-Girón
- Protozoal Respiratory Pathology Research Unit. Fundación INCLÍNICA, Calvo Sotelo, 16-3 dcha, 33007-Oviedo, Spain
| | - Hugo Cornelis van Woerden
- Institute of Primary Care & Public Health, Cardiff University School of Medicine, Neuadd Meirionnydd, Heath Park, Cardiff CF14 4YS, UK
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Caron DA. Towards a Molecular Taxonomy for Protists: Benefits, Risks, and Applications in Plankton Ecology. J Eukaryot Microbiol 2013; 60:407-13. [DOI: 10.1111/jeu.12044] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2013] [Accepted: 03/11/2013] [Indexed: 11/26/2022]
Affiliation(s)
- David A. Caron
- Department of Biological Sciences; University of Southern California; Los Angeles California
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10
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Gile GH, Carpenter KJ, James ER, Scheffrahn RH, Keeling PJ. Morphology and Molecular Phylogeny of Staurojoenina mulleri
sp. nov. (Trichonymphida, Parabasalia) from the Hindgut of the Kalotermitid Neotermes jouteli. J Eukaryot Microbiol 2013; 60:203-13. [DOI: 10.1111/jeu.12024] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2012] [Revised: 12/07/2012] [Accepted: 12/07/2012] [Indexed: 11/28/2022]
Affiliation(s)
- Gillian H. Gile
- Canadian Institute for Advanced Research; Department of Botany; University of British Columbia; Vancouver BC V6T 1Z4 Canada
| | - Kevin J. Carpenter
- Canadian Institute for Advanced Research; Department of Botany; University of British Columbia; Vancouver BC V6T 1Z4 Canada
| | - Erick R. James
- Canadian Institute for Advanced Research; Department of Botany; University of British Columbia; Vancouver BC V6T 1Z4 Canada
| | - Rudolf H. Scheffrahn
- University of Florida Research and Education Center; Fort Lauderdale Florida 33314 USA
| | - Patrick J. Keeling
- Canadian Institute for Advanced Research; Department of Botany; University of British Columbia; Vancouver BC V6T 1Z4 Canada
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Conrad MD, Bradic M, Warring SD, Gorman AW, Carlton JM. Getting trichy: tools and approaches to interrogating Trichomonas vaginalis in a post-genome world. Trends Parasitol 2012; 29:17-25. [PMID: 23219217 DOI: 10.1016/j.pt.2012.10.004] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2012] [Revised: 10/29/2012] [Accepted: 10/29/2012] [Indexed: 11/28/2022]
Abstract
Trichomonas vaginalis is a parasite of the urogenital tract in men and women, with a worldwide presence and significant implications for global public health. T. vaginalis research entered the age of genomics with the publication of the first genome sequence in 2007, but subsequent utilization of other 'omics' technologies and methods has been slow. Here, we review some of the tools and approaches available to interrogate T. vaginalis biology, with an emphasis on recent advances and current limitations, and draw attention to areas where further efforts are needed to examine effectively the complex and intriguing biology of the parasite.
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Affiliation(s)
- Melissa D Conrad
- Center for Genomics and Systems Biology, Department of Biology, New York University, New York, NY 10003, 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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Abstract
Despite the fact that the non-human primates are our closest relatives and represent a species-rich mammalian group, little is known about their intestinal protistan parasites/commensals. Particularly, the intestinal trichomonads represent a neglected part of the fauna of the primate digestive system. We have established 30 trichomonad strains isolated from feces of 11 primate species kept in 3 Czech zoos and performed an analysis of their SSU rDNA and ITS1-5·8S rDNA-ITS2. Our results showed that intestinal trichomonads are rather common among non-human primates. Molecular phylogenetic analysis showed that the strains are unexpectedly diversified, belonging to 8 or 9 distinct species. Interestingly, the vast majority of the strains from non-human primates belonged to the genus Tetratrichomonas while no member of this genus has been found in the human intestine so far. In addition, hominoid and non-hominoid primates differed in their intestinal trichomonads. Our results suggest that captive primates possibly may be infected by intestinal trichomonads of other vertebrates such as pigs, cattle, birds, tortoises and lizards.
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Malik SB, Brochu CD, Bilic I, Yuan J, Hess M, Logsdon JM, Carlton JM. Phylogeny of parasitic parabasalia and free-living relatives inferred from conventional markers vs. Rpb1, a single-copy gene. PLoS One 2011; 6:e20774. [PMID: 21695260 PMCID: PMC3111441 DOI: 10.1371/journal.pone.0020774] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2011] [Accepted: 05/09/2011] [Indexed: 12/25/2022] Open
Abstract
BACKGROUND Parabasalia are single-celled eukaryotes (protists) that are mainly comprised of endosymbionts of termites and wood roaches, intestinal commensals, human or veterinary parasites, and free-living species. Phylogenetic comparisons of parabasalids are typically based upon morphological characters and 18S ribosomal RNA gene sequence data (rDNA), while biochemical or molecular studies of parabasalids are limited to a few axenically cultivable parasites. These previous analyses and other studies based on PCR amplification of duplicated protein-coding genes are unable to fully resolve the evolutionary relationships of parabasalids. As a result, genetic studies of Parabasalia lag behind other organisms. PRINCIPAL FINDINGS Comparing parabasalid EF1α, α-tubulin, enolase and MDH protein-coding genes with information from the Trichomonas vaginalis genome reveals difficulty in resolving the history of species or isolates apart from duplicated genes. A conserved single-copy gene encodes the largest subunit of RNA polymerase II (Rpb1) in T. vaginalis and other eukaryotes. Here we directly sequenced Rpb1 degenerate PCR products from 10 parabasalid genera, including several T. vaginalis isolates and avian isolates, and compared these data by phylogenetic analyses. Rpb1 genes from parabasalids, diplomonads, Parabodo, Diplonema and Percolomonas were all intronless, unlike intron-rich homologs in Naegleria, Jakoba and Malawimonas. CONCLUSIONS/SIGNIFICANCE The phylogeny of Rpb1 from parasitic and free-living parabasalids, and conserved Rpb1 insertions, support Trichomonadea, Tritrichomonadea, and Hypotrichomonadea as monophyletic groups. These results are consistent with prior analyses of rDNA and GAPDH sequences and ultrastructural data. The Rpb1 phylogenetic tree also resolves species- and isolate-level relationships. These findings, together with the relative ease of Rpb1 isolation, make it an attractive tool for evaluating more extensive relationships within Parabasalia.
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Affiliation(s)
- Shehre-Banoo Malik
- Department of Microbiology, Division of Medical Parasitology, New York University School of Medicine, New York, New York, United States of America
- Department of Biology, Roy J. Carver Center for Comparative Genomics, University of Iowa, Iowa City, Iowa, United States of America
| | - Cynthia D. Brochu
- Department of Biology, Roy J. Carver Center for Comparative Genomics, University of Iowa, Iowa City, Iowa, United States of America
| | - Ivana Bilic
- Department for Farm Animals and Veterinary Public Health, Clinic for Avian, Reptile and Fish Medicine, University of Veterinary Medicine, Vienna, Austria
| | - Jing Yuan
- Department of Biology, Roy J. Carver Center for Comparative Genomics, University of Iowa, Iowa City, Iowa, United States of America
| | - Michael Hess
- Department for Farm Animals and Veterinary Public Health, Clinic for Avian, Reptile and Fish Medicine, University of Veterinary Medicine, Vienna, Austria
| | - John M. Logsdon
- Department of Biology, Roy J. Carver Center for Comparative Genomics, University of Iowa, Iowa City, Iowa, United States of America
| | - Jane M. Carlton
- Department of Microbiology, Division of Medical Parasitology, New York University School of Medicine, New York, New York, United States of America
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