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Tikhonenkov DV, Gawryluk RMR, Mylnikov AP, Keeling PJ. First finding of free-living representatives of Prokinetoplastina and their nuclear and mitochondrial genomes. Sci Rep 2021; 11:2946. [PMID: 33536456 PMCID: PMC7859406 DOI: 10.1038/s41598-021-82369-z] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2020] [Accepted: 01/19/2021] [Indexed: 01/30/2023] Open
Abstract
Kinetoplastids are heterotrophic flagellated protists, including important parasites of humans and animals (trypanosomatids), and ecologically important free-living bacterial consumers (bodonids). Phylogenies have shown that the earliest-branching kinetoplastids are all parasites or obligate endosymbionts, whose highly-derived state makes reconstructing the ancestral state of the group challenging. We have isolated new strains of unusual free-living flagellates that molecular phylogeny shows to be most closely related to endosymbiotic and parasitic Perkinsela and Ichthyobodo species that, together with unidentified environmental sequences, form the clade at the base of kinetoplastids. These strains are therefore the first described free-living prokinetoplastids, and potentially very informative in understanding the evolution and ancestral states of morphological and molecular characteristics described in other kinetoplastids. Overall, we find that these organisms morphologically and ultrastructurally resemble some free-living bodonids and diplonemids, and possess nuclear genomes with few introns, polycistronic mRNA expression, high coding density, and derived traits shared with other kinetoplastids. Their genetic repertoires are more diverse than the best-studied free-living kinetoplastids, which is likely a reflection of their higher metabolic potential. Mitochondrial RNAs of these new species undergo the most extensive U insertion/deletion editing reported so far, and limited deaminative C-to-U and A-to-I editing, but we find no evidence for mitochondrial trans-splicing.
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Affiliation(s)
- Denis V. Tikhonenkov
- grid.4886.20000 0001 2192 9124Papanin Institute for Biology of Inland Waters, Russian Academy of Sciences, Borok, 152742 Russia ,grid.446209.d0000 0000 9203 3563AquaBioSafe Laboratory, University of Tyumen, 625003 Tyumen, Russia
| | - Ryan M. R. Gawryluk
- grid.143640.40000 0004 1936 9465Department of Biology, University of Victoria, Victoria, British Columbia V8W 2Y2 Canada
| | - Alexander P. Mylnikov
- grid.4886.20000 0001 2192 9124Papanin Institute for Biology of Inland Waters, Russian Academy of Sciences, Borok, 152742 Russia
| | - Patrick J. Keeling
- grid.17091.3e0000 0001 2288 9830Department of Botany, University of British Columbia, Vancouver, British Columbia V6T 1Z4 Canada
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Wideman JG, Lax G, Leonard G, Milner DS, Rodríguez-Martínez R, Simpson AGB, Richards TA. A single-cell genome reveals diplonemid-like ancestry of kinetoplastid mitochondrial gene structure. Philos Trans R Soc Lond B Biol Sci 2019; 374:20190100. [PMID: 31587636 PMCID: PMC6792441 DOI: 10.1098/rstb.2019.0100] [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] [Indexed: 12/24/2022] Open
Abstract
Euglenozoa comprises euglenids, kinetoplastids, and diplonemids, with each group exhibiting different and highly unusual mitochondrial genome organizations. Although they are sister groups, kinetoplastids and diplonemids have very distinct mitochondrial genome architectures, requiring widespread insertion/deletion RNA editing and extensive trans-splicing, respectively, in order to generate functional transcripts. The evolutionary history by which these differing processes arose remains unclear. Using single-cell genomics, followed by small sub unit ribosomal DNA and multigene phylogenies, we identified an isolated marine cell that branches on phylogenetic trees as a sister to known kinetoplastids. Analysis of single-cell amplified genomic material identified multiple mitochondrial genome contigs. These revealed a gene architecture resembling that of diplonemid mitochondria, with small fragments of genes encoded out of order and or on different contigs, indicating that these genes require extensive trans-splicing. Conversely, no requirement for kinetoplastid-like insertion/deletion RNA-editing was detected. Additionally, while we identified some proteins so far only found in kinetoplastids, we could not unequivocally identify mitochondrial RNA editing proteins. These data invite the hypothesis that extensive genome fragmentation and trans-splicing were the ancestral states for the kinetoplastid-diplonemid clade but were lost during the kinetoplastid radiation. This study demonstrates that single-cell approaches can successfully retrieve lineages that represent important new branches on the tree of life, and thus can illuminate major evolutionary and functional transitions in eukaryotes. This article is part of a discussion meeting issue ‘Single cell ecology’.
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Affiliation(s)
- Jeremy G Wideman
- Living Systems Institute, University of Exeter, Stocker Road, Exeter EX4 4QD, UK.,Department of Biochemistry and Molecular Biology, Dalhousie University, Halifax, Nova Scotia, Canada B3H 4R2
| | - Gordon Lax
- Department of Biology and Centre for Comparative Genomics and Evolutionary Bioinformatics, Dalhousie University, Halifax, Nova Scotia, Canada B3H 4R2
| | - Guy Leonard
- Living Systems Institute, University of Exeter, Stocker Road, Exeter EX4 4QD, UK
| | - David S Milner
- Living Systems Institute, University of Exeter, Stocker Road, Exeter EX4 4QD, UK
| | - Raquel Rodríguez-Martínez
- Living Systems Institute, University of Exeter, Stocker Road, Exeter EX4 4QD, UK.,Laboratorio de Complejidad Microbiana y Ecología Funcional, Instituto Antofagasta, Universidad de Antofagasta, Antofagasta, Chile
| | - Alastair G B Simpson
- Department of Biology and Centre for Comparative Genomics and Evolutionary Bioinformatics, Dalhousie University, Halifax, Nova Scotia, Canada B3H 4R2
| | - Thomas A Richards
- Living Systems Institute, University of Exeter, Stocker Road, Exeter EX4 4QD, UK
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Horizontal Gene Transfer as an Indispensable Driver for Evolution of Neocallimastigomycota into a Distinct Gut-Dwelling Fungal Lineage. Appl Environ Microbiol 2019; 85:AEM.00988-19. [PMID: 31126947 DOI: 10.1128/aem.00988-19] [Citation(s) in RCA: 52] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2019] [Accepted: 05/19/2019] [Indexed: 01/01/2023] Open
Abstract
Survival and growth of the anaerobic gut fungi (AGF; Neocallimastigomycota) in the herbivorous gut necessitate the possession of multiple abilities absent in other fungal lineages. We hypothesized that horizontal gene transfer (HGT) was instrumental in forging the evolution of AGF into a phylogenetically distinct gut-dwelling fungal lineage. The patterns of HGT were evaluated in the transcriptomes of 27 AGF strains, 22 of which were isolated and sequenced in this study, and 4 AGF genomes broadly covering the breadth of AGF diversity. We identified 277 distinct incidents of HGT in AGF transcriptomes, with subsequent gene duplication resulting in an HGT frequency of 2 to 3.5% in AGF genomes. The majority of HGT events were AGF specific (91.7%) and wide (70.8%), indicating their occurrence at early stages of AGF evolution. The acquired genes allowed AGF to expand their substrate utilization range, provided new venues for electron disposal, augmented their biosynthetic capabilities, and facilitated their adaptation to anaerobiosis. The majority of donors were anaerobic fermentative bacteria prevalent in the herbivorous gut. This study strongly indicates that HGT indispensably forged the evolution of AGF as a distinct fungal phylum and provides a unique example of the role of HGT in shaping the evolution of a high-rank taxonomic eukaryotic lineage.IMPORTANCE The anaerobic gut fungi (AGF) represent a distinct basal phylum lineage (Neocallimastigomycota) commonly encountered in the rumen and alimentary tracts of herbivores. Survival and growth of anaerobic gut fungi in these anaerobic, eutrophic, and prokaryote-dominated habitats necessitates the acquisition of several traits absent in other fungal lineages. We assess here the role of horizontal gene transfer as a relatively fast mechanism for trait acquisition by the Neocallimastigomycota postsequestration in the herbivorous gut. Analysis of 27 transcriptomes that represent the broad diversity of Neocallimastigomycota identified 277 distinct HGT events, with subsequent gene duplication resulting in an HGT frequency of 2 to 3.5% in AGF genomes. These HGT events have allowed AGF to survive in the herbivorous gut by expanding their substrate utilization range, augmenting their biosynthetic pathway, providing new routes for electron disposal by expanding fermentative capacities, and facilitating their adaptation to anaerobiosis. HGT in the AGF is also shown to be mainly a cross-kingdom affair, with the majority of donors belonging to the bacteria. This study represents a unique example of the role of HGT in shaping the evolution of a high-rank taxonomic eukaryotic lineage.
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Vesteg M, Hadariová L, Horváth A, Estraño CE, Schwartzbach SD, Krajčovič J. Comparative molecular cell biology of phototrophic euglenids and parasitic trypanosomatids sheds light on the ancestor of Euglenozoa. Biol Rev Camb Philos Soc 2019; 94:1701-1721. [PMID: 31095885 DOI: 10.1111/brv.12523] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2018] [Revised: 04/30/2019] [Accepted: 05/02/2019] [Indexed: 01/23/2023]
Abstract
Parasitic trypanosomatids and phototrophic euglenids are among the most extensively studied euglenozoans. The phototrophic euglenid lineage arose relatively recently through secondary endosymbiosis between a phagotrophic euglenid and a prasinophyte green alga that evolved into the euglenid secondary chloroplast. The parasitic trypanosomatids (i.e. Trypanosoma spp. and Leishmania spp.) and the freshwater phototrophic euglenids (i.e. Euglena gracilis) are the most evolutionary distant lineages in the Euglenozoa phylogenetic tree. The molecular and cell biological traits they share can thus be considered as ancestral traits originating in the common euglenozoan ancestor. These euglenozoan ancestral traits include common mitochondrial presequence motifs, respiratory chain complexes containing various unique subunits, a unique ATP synthase structure, the absence of mitochondria-encoded transfer RNAs (tRNAs), a nucleus with a centrally positioned nucleolus, closed mitosis without dissolution of the nuclear membrane and nucleoli, a nuclear genome containing the unusual 'J' base (β-D-glucosyl-hydroxymethyluracil), processing of nucleus-encoded precursor messenger RNAs (pre-mRNAs) via spliced-leader RNA (SL-RNA) trans-splicing, post-transcriptional gene silencing by the RNA interference (RNAi) pathway and the absence of transcriptional regulation of nuclear gene expression. Mitochondrial uridine insertion/deletion RNA editing directed by guide RNAs (gRNAs) evolved in the ancestor of the kinetoplastid lineage. The evolutionary origin of other molecular features known to be present only in either kinetoplastids (i.e. polycistronic transcripts, compaction of nuclear genomes) or euglenids (i.e. monocistronic transcripts, huge genomes, many nuclear cis-spliced introns, polyproteins) is unclear.
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Affiliation(s)
- Matej Vesteg
- Department of Biology and Ecology, Faculty of Natural Sciences, Matej Bel University, 974 01, Banská Bystrica, Slovakia
| | - Lucia Hadariová
- Biotechnology and Biomedicine Center of the Academy of Sciences and Charles University in Vestec (BIOCEV), 252 50, Vestec, Czech Republic.,Department of Parasitology, Faculty of Science, Charles University in Prague, 128 44, Prague, Czech Republic
| | - Anton Horváth
- Department of Biochemistry, Faculty of Natural Sciences, Comenius University, 842 15, Bratislava, Slovakia
| | - Carlos E Estraño
- Department of Biological Sciences, University of Memphis, Memphis, TN, 38152-3560, USA
| | - Steven D Schwartzbach
- Department of Biological Sciences, University of Memphis, Memphis, TN, 38152-3560, USA
| | - Juraj Krajčovič
- Department of Biology, Faculty of Natural Sciences, University of ss. Cyril and Methodius, 917 01, Trnava, Slovakia
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5
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Okamoto N, Gawryluk RMR, Del Campo J, Strassert JFH, Lukeš J, Richards TA, Worden AZ, Santoro AE, Keeling PJ. A Revised Taxonomy of Diplonemids Including the Eupelagonemidae n. fam. and a Type Species, Eupelagonema oceanica n. gen. & sp. J Eukaryot Microbiol 2018; 66:519-524. [PMID: 30080299 DOI: 10.1111/jeu.12679] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2017] [Revised: 06/16/2018] [Accepted: 07/12/2018] [Indexed: 12/20/2022]
Abstract
Recent surveys of marine microbial diversity have identified a previously unrecognized lineage of diplonemid protists as being among the most diverse heterotrophic eukaryotes in global oceans. Despite their monophyly (and assumed importance), they lack a formal taxonomic description, and are informally known as deep-sea pelagic diplonemids (DSPDs) or marine diplonemids. Recently, we documented morphology and molecular sequences from several DSPDs, one of which is particularly widespread and abundant in environmental sequence data. To simplify the communication of future work on this important group, here we formally propose to erect the family Eupelagonemidae to encompass this clade, as well as a formal genus and species description for the apparently most abundant phylotype, Eupelagonema oceanica, for which morphological information and single-cell amplified genome data are currently available.
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Affiliation(s)
- Noriko Okamoto
- Department of Botany, University of British Columbia, 3529-6270 University Boulevard, Boulevard, British Columbia, Canada
| | - Ryan M R Gawryluk
- Department of Botany, University of British Columbia, 3529-6270 University Boulevard, Boulevard, British Columbia, Canada
| | - Javier Del Campo
- Department of Botany, University of British Columbia, 3529-6270 University Boulevard, Boulevard, British Columbia, Canada
| | - Jürgen F H Strassert
- Department of Botany, University of British Columbia, 3529-6270 University Boulevard, Boulevard, British Columbia, Canada
| | - Julius Lukeš
- Institute of Parasitology, Biology Centre, Czech Academy of Sciences, Faculty of Sciences, University of South Bohemia, Branišovská 31, 370 05, České Budějovice (Budweis), Czech Republic
| | - Thomas A Richards
- Biosciences, University of Exeter, Geoffrey Pope Building, Exeter, EX4 4QD, United Kingdom
| | - Alexandra Z Worden
- Monterey Bay Aquarium Research Institute, Moss Landing, California, 95039, USA
| | - Alyson E Santoro
- Department of Ecology, Evolution and Marine Biology, University of California, Santa Barbara, California, 93106, USA
| | - Patrick J Keeling
- Department of Botany, University of British Columbia, 3529-6270 University Boulevard, Boulevard, British Columbia, Canada
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6
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Morphological Identification and Single-Cell Genomics of Marine Diplonemids. Curr Biol 2016; 26:3053-3059. [DOI: 10.1016/j.cub.2016.09.013] [Citation(s) in RCA: 76] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2016] [Revised: 08/25/2016] [Accepted: 09/07/2016] [Indexed: 11/19/2022]
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Makiuchi T, Annoura T, Hashimoto M, Hashimoto T, Aoki T, Nara T. Compartmentalization of a glycolytic enzyme in Diplonema, a non-kinetoplastid euglenozoan. Protist 2011; 162:482-9. [PMID: 21377422 DOI: 10.1016/j.protis.2010.11.003] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2010] [Accepted: 11/23/2010] [Indexed: 11/18/2022]
Abstract
Glycosomes are peroxisome-related organelles containing glycolytic enzymes that have been found only in kinetoplastids. We show here that a glycolytic enzyme is compartmentalized in diplonemids, the sister group of kinetoplastids. We found that, similar to kinetoplastid aldolases, the fructose 1,6-bisphosphate aldolase of Diplonema papillatum possesses a type 2-peroxisomal targeting signal. Western blotting showed that this aldolase was present predominantly in the membrane/organellar fraction. Immunofluorescence analysis showed that this aldolase had a scattered distribution in the cytosol, suggesting its compartmentalization. In contrast, orotidine-5'-monophosphate decarboxylase, a non-glycolytic glycosomal enzyme in kinetoplastids, was shown to be a cytosolic enzyme in D. papillatum. Since euglenoids, the earliest diverging branch of Euglenozoa, do not possess glycolytic compartments, these findings suggest that the routing of glycolytic enzymes into peroxisomes may have occurred in a common ancestor of diplonemids and kinetoplastids, followed by diversification of these newly established organelles in each of these euglenozoan lineages.
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Affiliation(s)
- Takashi Makiuchi
- Department of Molecular and Cellular Parasitology, Juntendo University School of Medicine, 2-1-1 Hongo, Bunkyo-ku, Tokyo 113-8421, Japan
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Abstract
The carotenoids constitute the most widespread class of pigments in nature. Most previous work has concentrated on the identification and characterization of their chemical physical properties and bioavailability. In recent years, significant amounts of research have been conducted in an attempt to analyze the genes and the molecular regulation of the genes involved in the biosynthesis of carotenoids. However, it is important not to lose sight of the early evolution of carotenoid biosynthesis. One of the major obstacles in understanding the evolution of the respective enzymes and their patterns of selection is a lack of a well-supported phylogenic analysis. In the present research, a major long-term objective was to provide a clearer picture of the evolutionary history of genes, together with an evaluation of the patterns of selection in algae. These phylogenies will be important in studies characterizing the evolution of algae. The gene sequences of the enzymes involved in the major steps of the carotenoid biosynthetic pathway in algae (cyanobacteria, rhofophyta, chlorophyta) have been analyzed. Phylogenetic relationships among protein-coding DNA sequences were reconstructed by neighbor-joining (NJ) analysis for the respective carotenoid biosynthetic pathway genes (crt) in algae. The analysis also contains an estimation of the rate of nonsynonymous nucleotide substitutions per nonsynonymous site (d(N)), synonymous nucleotide substitution per synonymous site (d(S)), and the ratio of nonsynonmous (d(N)/d(S)) for the test of selection patterns. The phylogenetic trees show that the taxa of some genera have a closer evolutionary relationship with other genera in some gene sequences, which suggests a common ancient origin and that lateral gene transfer has occurred among unrelated genera. The d(N) values of crt genes in the early pathway are relatively low, while those of the following steps are slightly higher, while the d(N) values of crt genes in chlorophyta are higher than those in cyanobacteria. Most of the d(N)/d(S) values exceed 1. The phylogenetic analysis revealed that lateral gene transfer may have taken place across algal genomes and the d(N) values suggest that most of the early crt genes are well conserved compared to the later crt genes. Furthermore, d(N) values also revealed that the crt genes of chlorophyta are more evolutionary than cyanobacteria. The amino acids' changes are mostly adaptive evolution under the influence of positive diversity selection.
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Affiliation(s)
- Qian Chen
- College of Food and Bioengineering, South China University of Technology, Guangzhou, People's Republic of China
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9
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Bafana A, Chakrabarti T. Lateral gene transfer in phylogeny of azoreductase enzyme. Comput Biol Chem 2008; 32:191-7. [PMID: 18440871 DOI: 10.1016/j.compbiolchem.2008.03.003] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2007] [Revised: 03/18/2008] [Accepted: 03/19/2008] [Indexed: 10/22/2022]
Abstract
This paper attempts to reconstruct the phylogeny of azoreductase enzyme from different organisms and compare it with the small subunit rRNA-based phylogeny of the organisms. The two phylogenies were found to be incongruent, indicating several events of lateral transfer of azoreductase gene between phylogenetically diverse organisms. However, the phylogenetic analysis methods have several limitations and a single method may not give the true pattern. Hence, it is necessary to corroborate the results with other complementary analysis tools. We used several tools to test our hypothesis of lateral transfer and found that it was supported not only by the analysis of the whole sequences, but also by the conserved motifs detected in these sequences. There were ample evidences for lateral transfer of azoreductase gene among enteric bacteria. There were also indications that azoreductase probably evolved in prokaryotes and then it was laterally transferred to eukaryotes in multiple events, resulting in some sequence variation among eukaryotic azoreductases. Finally, profile HMMs and conserved motifs extracted from these azoreductase sequences were found to provide sensitive tools for identifying potential azoreductases from the database. The analysis techniques used in this study can be extended to other gene trees to verify their evolutionary histories.
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Affiliation(s)
- Amit Bafana
- Environmental Biotechnology Division, National Environmental Engineering Research Institute, Nehru Marg, Nagpur, India.
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10
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Eukaryotic origin of glyceraldehyde-3-phosphate dehydrogenase genes in Clostridium thermocellum and Clostridium cellulolyticum genomes and putative fates of the exogenous gene in the subsequent genome evolution. Gene 2008; 441:22-7. [PMID: 18420358 DOI: 10.1016/j.gene.2008.03.001] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2007] [Accepted: 03/04/2008] [Indexed: 11/20/2022]
Abstract
Although lateral gene transfer (LGT) events have been frequently documented in the evolution of glyceraldehyde-3-phosphate dehydrogenase (GAPDH), no eukaryote-to-prokaryote transfer has been reported so far. Here we describe the first case of the GAPDH gene transfer from a eukaryote to a subset of Clostridium species (Bacteria, Firmicutes). A series of phylogenetic analyses of GAPDH homologues revealed that Clostridium thermocellum and Clostridium cellulolyticum homologues have the evolutionary affinity to the eukaryotic homologues, rather than to those of bacterial species closely related to the two Clostridium species in the organismal phylogeny. These results suggest that the GAPDH genes in the two Clostridium species are of eukaryotic origin, which is the first reported case of eukaryote-to-bacterium GAPDH gene transfer. Since a previously published 16S ribosomal DNA phylogeny and our GAPDH phylogeny commonly suggest an intimate evolutionary relationship between C. thermocellum and C. cellulolyticum, a common ancestor of the two species likely acquired the eukaryotic GAPDH gene. In the C. cellulolyticum genome, the exogenous GAPDH gene was physically separated from other glycolytic genes, suggesting that this gene organization was likely achieved by a random insertion of the laterally transferred gene. On the other hand, in the C. thermocellum genome, the laterally transferred GAPDH gene clusters with other bacterial glycolytic genes. We discuss possible scenarios for the evolutionarily chimeric glycolytic gene cluster in the C. thermocellum genome.
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A complex and punctate distribution of three eukaryotic genes derived by lateral gene transfer. BMC Evol Biol 2007; 7:89. [PMID: 17562012 PMCID: PMC1920508 DOI: 10.1186/1471-2148-7-89] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2007] [Accepted: 06/11/2007] [Indexed: 11/13/2022] Open
Abstract
Background Lateral gene transfer is increasingly invoked to explain phylogenetic results that conflict with our understanding of organismal relationships. In eukaryotes, the most common observation interpreted in this way is the appearance of a bacterial gene (one that is not clearly derived from the mitochondrion or plastid) in a eukaryotic nuclear genome. Ideally such an observation would involve a single eukaryote or a small group of related eukaryotes encoding a gene from a specific bacterial lineage. Results Here we show that several apparently simple cases of lateral transfer are actually more complex than they originally appeared: in these instances we find that two or more distantly related eukaryotic groups share the same bacterial gene, resulting in a punctate distribution. Specifically, we describe phylogenies of three core carbon metabolic enzymes: transketolase, glyceraldehyde-3-phosphate dehydrogenase and ribulose-5-phosphate-3-epimerase. Phylogenetic trees of each of these enzymes includes a strongly-supported clade consisting of several eukaryotes that are distantly related at the organismal level, but whose enzymes are apparently all derived from the same lateral transfer. With less sampling any one of these examples would appear to be a simple case of bacterium-to-eukaryote lateral transfer; taken together, their evolutionary histories cannot be so simple. The distributions of these genes may represent ancient paralogy events or genes that have been transferred from bacteria to an ancient ancestor of the eukaryotes that retain them. They may alternatively have been transferred laterally from a bacterium to a single eukaryotic lineage and subsequently transferred between distantly related eukaryotes. Conclusion Determining how complex the distribution of a transferred gene is depends on the sampling available. These results show that seemingly simple cases may be revealed to be more complex with greater sampling, suggesting many bacterial genes found in eukaryotic genomes may have a punctate distribution.
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12
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Robbens S, Petersen J, Brinkmann H, Rouzé P, Van de Peer Y. Unique Regulation of the Calvin Cycle in the Ultrasmall Green Alga Ostreococcus. J Mol Evol 2007; 64:601-4. [PMID: 17457634 DOI: 10.1007/s00239-006-0159-y] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2006] [Accepted: 02/02/2007] [Indexed: 10/23/2022]
Abstract
Glyceraldehyde-3-phosphate dehydrogenase (GapAB) and CP12 are two major players in controlling the inactivation of the Calvin cycle in land plants at night. GapB originated from a GapA gene duplication and differs from GapA by the presence of a specific C-terminal extension that was recruited from CP12. While GapA and CP12 are assumed to be generally present in the Plantae (glaucophytes, red and green algae, and plants), up to now GapB was exclusively found in Streptophyta, including the enigmatic green alga Mesostigma viride. However, here we show that two closely related prasinophycean green algae, Ostreococcus tauri and Ostreococcus lucimarinus, also possess a GapB gene, while CP12 is missing. This remarkable finding either antedates the GapA/B gene duplication or indicates a lateral recruitment. Moreover, Ostreococcus is the first case where the crucial CP12 function may be completely replaced by GapB-mediated GapA/B aggregation.
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13
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Stechmann A, Baumgartner M, Silberman JD, Roger AJ. The glycolytic pathway of Trimastix pyriformis is an evolutionary mosaic. BMC Evol Biol 2006; 6:101. [PMID: 17123440 PMCID: PMC1665464 DOI: 10.1186/1471-2148-6-101] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2006] [Accepted: 11/23/2006] [Indexed: 11/29/2022] Open
Abstract
Background Glycolysis and subsequent fermentation is the main energy source for many anaerobic organisms. The glycolytic pathway consists of ten enzymatic steps which appear to be universal amongst eukaryotes. However, it has been shown that the origins of these enzymes in specific eukaryote lineages can differ, and sometimes involve lateral gene transfer events. We have conducted an expressed sequence tag (EST) survey of the anaerobic flagellate Trimastix pyriformis to investigate the nature of the evolutionary origins of the glycolytic enzymes in this relatively unstudied organism. Results We have found genes in the Trimastix EST data that encode enzymes potentially catalyzing nine of the ten steps of the glycolytic conversion of glucose to pyruvate. Furthermore, we have found two different enzymes that in principle could catalyze the conversion of phosphoenol pyruvate (PEP) to pyruvate (or the reverse reaction) as part of the last step in glycolysis. Our phylogenetic analyses of all of these enzymes revealed at least four cases where the relationship of the Trimastix genes to homologs from other species is at odds with accepted organismal relationships. Although lateral gene transfer events likely account for these anomalies, with the data at hand we were not able to establish with confidence the bacterial donor lineage that gave rise to the respective Trimastix enzymes. Conclusion A number of the glycolytic enzymes of Trimastix have been transferred laterally from bacteria instead of being inherited from the last common eukaryotic ancestor. Thus, despite widespread conservation of the glycolytic biochemical pathway across eukaryote diversity, in a number of protist lineages the enzymatic components of the pathway have been replaced by lateral gene transfer from disparate evolutionary sources. It remains unclear if these replacements result from selectively advantageous properties of the introduced enzymes or if they are neutral outcomes of a gene transfer 'ratchet' from food or endosymbiotic organisms or a combination of both processes.
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Affiliation(s)
- Alexandra Stechmann
- Department of Biochemistry and Molecular Biology, Dalhousie University, Sir Charles Tupper Building, Halifax, Canada
| | - Manuela Baumgartner
- Department of Biochemistry and Molecular Biology, Dalhousie University, Sir Charles Tupper Building, Halifax, Canada
- Department für Biologie I, Botanik, Ludwig-Maximilians-Universität München, Menzingerstraße 67, D-80638 München, Germany
| | - Jeffrey D Silberman
- Department of Biochemistry and Molecular Biology, Dalhousie University, Sir Charles Tupper Building, Halifax, Canada
- Department of Biological Sciences, University of Arkansas, Fayetteville, AR 72701, USA
| | - Andrew J Roger
- Department of Biochemistry and Molecular Biology, Dalhousie University, Sir Charles Tupper Building, Halifax, Canada
- Canadian Institute for Advanced Research, Evolutionary Biology Program, Dalhousie University, Sir Charles Tupper Building, Halifax, Canada
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14
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Watkins RF, Gray MW. The frequency of eubacterium-to-eukaryote lateral gene transfers shows significant cross-taxa variation within amoebozoa. J Mol Evol 2006; 63:801-14. [PMID: 17086451 DOI: 10.1007/s00239-006-0031-0] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2006] [Accepted: 04/20/2006] [Indexed: 10/24/2022]
Abstract
Single-celled bacterivorous eukaryotes offer excellent test cases for evaluation of the frequency of prey-to-predator lateral gene transfer (LGT). Here we use analysis of expressed sequence tag (EST) data sets to quantify the extent of LGT from eubacteria to two amoebae, Acanthamoeba castellanii and Hartmannella vermiformis. Stringent screening for LGT proceeded in several steps intended to enrich for authentic events while at the same time minimizing the incidence of false positives due to factors such as limitations in database coverage and ancient paralogy. The results were compared with data obtained when the same methodology was applied to EST libraries from a number of other eukaryotic taxa. Significant differences in the extent of apparent eubacterium-to-eukaryote LGT were found between taxa. Our results indicate that there may be substantial inter-taxon variation in the number of LGT events that become fixed even between amoebozoan species that have similar feeding modalities.
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Affiliation(s)
- Russell F Watkins
- Centre for Molecular Medicine and Therapeutics, Child & Family Research Institute, and Department of Medical Genetics, University of British Columbia, Vancouver, British Columbia, V5Z 4H4, Canada.
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Zeng J, Wang Y, Shen G, Zheng X. A Phytophthora sojae gene of glyceraldehyde-3-phosphate dehydrogenase (GAPDH) induced in host infection and its anti-oxidative function in yeast. CHINESE SCIENCE BULLETIN-CHINESE 2006. [DOI: 10.1007/s11434-006-1316-9] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Takishita K, Ishida KI, Maruyama T. An Enigmatic GAPDH Gene in the Symbiotic Dinoflagellate Genus Symbiodinium and its Related Species (the Order Suessiales): Possible Lateral Gene Transfer between Two Eukaryotic Algae, Dinoflagellate and Euglenophyte. Protist 2003; 154:443-54. [PMID: 14658500 DOI: 10.1078/143446103322454176] [Citation(s) in RCA: 40] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
A group of unicellular eukaryotic algae, the dinoflagellates, are known to possess two types of gene for glyceraldehyde-3-phosphate dehydrogenase (GAPDH). An enzyme encoded by one type of gene possibly plays a key role in the glycolytic pathway of the cytosol and the other in the Calvin cycle of plastids. In the present study, an additional type of GAPDH gene (GapC3) was found in the symbiotic dinoflagellates, Symbiodinium spp. and their related species, Gymnodinium simplex and Polarella glacialis, all of which belong to the order Suessiales. Since no intracellular translocation signal is found at both amino- and carboxy-termini of its deduced amino acid sequence, the protein is predicted to function in the cytosol. However, it may not be involved in glycolysis due to the presence of an amino acid signature that allows binding for NADP+. It is likely that dinoflagellate species, other than Suessiales investigated in this study, lack this type of GAPDH. Phylogenetic analysis placed GapC3 from the Suessialean species firmly in the clade composed of GAPDH from spirochetes, euglenophytes (cytosolic type) and kinetoplastids (glycosomal type). Specifically, this enigmatic GAPDH gene in dinoflagellates was closely related to its cytosolic counterpart in euglenophytes. It has been previously reported that plastid-targeted (Calvin cycle) GAPDH genes of the dinoflagellates Pyrocystis spp. and that of the euglenophyte Euglena gracilis also seem to share a common ancestor. It appears highly likely that at least two genes (cytosolic and plastid-targeted GAPDH genes) have been laterally transferred between these two eukaryotic algal groups.
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Archibald JM, Rogers MB, Toop M, Ishida KI, Keeling PJ. Lateral gene transfer and the evolution of plastid-targeted proteins in the secondary plastid-containing alga Bigelowiella natans. Proc Natl Acad Sci U S A 2003; 100:7678-83. [PMID: 12777624 PMCID: PMC164647 DOI: 10.1073/pnas.1230951100] [Citation(s) in RCA: 172] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2003] [Accepted: 04/18/2003] [Indexed: 02/01/2023] Open
Abstract
Chlorarachniophytes are amoeboflagellate algae that acquired photosynthesis secondarily by engulfing a green alga and retaining its plastid (chloroplast). An important consequence of secondary endosymbiosis in chlorarachniophytes is that most of the nuclear genes encoding plastid-targeted proteins have moved from the nucleus of the endosymbiont to the host nucleus. We have sequenced and analyzed 83 cDNAs encoding 78 plastid-targeted proteins from the model chlorarachniophyte Bigelowiella natans (formerly Chlorarachnion sp. CCMP621). Phylogenies inferred from the majority of these genes are consistent with a chlorophyte green algal origin. However, a significant number of genes ( approximately 21%) show signs of having been acquired by lateral gene transfer from numerous other sources: streptophyte algae, red algae (or algae with red algal endosymbionts), as well as bacteria. The chlorarachniophyte plastid proteome may therefore be regarded as a mosaic derived from various organisms in addition to the ancestral chlorophyte plastid. In contrast, the homologous genes from the chlorophyte Chlamydomonas reinhardtii do not show any indications of lateral gene transfer. This difference is likely a reflection of the mixotrophic nature of Bigelowiella (i.e., it is photosynthetic and phagotrophic), whereas Chlamydomonas is strictly autotrophic. These results underscore the importance of lateral gene transfer in contributing foreign proteins to eukaryotic cells and their organelles, and also suggest that its impact can vary from lineage to lineage.
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Affiliation(s)
- John M Archibald
- Canadian Institute for Advanced Research, Program in Evolutionary Biology, Department of Botany, University of British Columbia, 3529-6270 University Boulevard, Vancouver, BC, Canada V6T 1Z4
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Andersson JO, Roger AJ. Evolution of glutamate dehydrogenase genes: evidence for lateral gene transfer within and between prokaryotes and eukaryotes. BMC Evol Biol 2003; 3:14. [PMID: 12820901 PMCID: PMC166173 DOI: 10.1186/1471-2148-3-14] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2003] [Accepted: 06/23/2003] [Indexed: 11/29/2022] Open
Abstract
BACKGROUND Lateral gene transfer can introduce genes with novel functions into genomes or replace genes with functionally similar orthologs or paralogs. Here we present a study of the occurrence of the latter gene replacement phenomenon in the four gene families encoding different classes of glutamate dehydrogenase (GDH), to evaluate and compare the patterns and rates of lateral gene transfer (LGT) in prokaryotes and eukaryotes. RESULTS We extend the taxon sampling of gdh genes with nine new eukaryotic sequences and examine the phylogenetic distribution pattern of the various GDH classes in combination with maximum likelihood phylogenetic analyses. The distribution pattern analyses indicate that LGT has played a significant role in the evolution of the four gdh gene families. Indeed, a number of gene transfer events are identified by phylogenetic analyses, including numerous prokaryotic intra-domain transfers, some prokaryotic inter-domain transfers and several inter-domain transfers between prokaryotes and microbial eukaryotes (protists). CONCLUSION LGT has apparently affected eukaryotes and prokaryotes to a similar extent within the gdh gene families. In the absence of indications that the evolution of the gdh gene families is radically different from other families, these results suggest that gene transfer might be an important evolutionary mechanism in microbial eukaryote genome evolution.
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Affiliation(s)
- Jan O Andersson
- The Canadian Institute for Advanced Research, Program in Evolutionary Biology, Department of Biochemistry & Molecular Biology, Dalhousie University, Sir Charles Tupper Medical Building, Halifax, Nova Scotia, B3H 1X5, Canada
- Current address: Institute of Cell and Molecular Biology, Uppsala University, Biomedical Center, Box 596, S-751 24 Uppsala, Sweden
| | - Andrew J Roger
- The Canadian Institute for Advanced Research, Program in Evolutionary Biology, Department of Biochemistry & Molecular Biology, Dalhousie University, Sir Charles Tupper Medical Building, Halifax, Nova Scotia, B3H 1X5, Canada
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Richards TA, Hirt RP, Williams BAP, Embley TM. Horizontal gene transfer and the evolution of parasitic protozoa. Protist 2003; 154:17-32. [PMID: 12812367 DOI: 10.1078/143446103764928468] [Citation(s) in RCA: 71] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
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Emelyanov VV. Mitochondrial connection to the origin of the eukaryotic cell. EUROPEAN JOURNAL OF BIOCHEMISTRY 2003; 270:1599-618. [PMID: 12694174 DOI: 10.1046/j.1432-1033.2003.03499.x] [Citation(s) in RCA: 86] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Phylogenetic evidence is presented that primitively amitochondriate eukaryotes containing the nucleus, cytoskeleton, and endomembrane system may have never existed. Instead, the primary host for the mitochondrial progenitor may have been a chimeric prokaryote, created by fusion between an archaebacterium and a eubacterium, in which eubacterial energy metabolism (glycolysis and fermentation) was retained. A Rickettsia-like intracellular symbiont, suggested to be the last common ancestor of the family Rickettsiaceae and mitochondria, may have penetrated such a host (pro-eukaryote), surrounded by a single membrane, due to tightly membrane-associated phospholipase activity, as do present-day rickettsiae. The relatively rapid evolutionary conversion of the invader into an organelle may have occurred in a safe milieu via numerous, often dramatic, changes involving both partners, which resulted in successful coupling of the host glycolysis and the symbiont respiration. Establishment of a potent energy-generating organelle made it possible, through rapid dramatic changes, to develop genuine eukaryotic elements. Such sequential, or converging, global events could fill the gap between prokaryotes and eukaryotes known as major evolutionary discontinuity.
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Doolittle WF, Boucher Y, Nesbø CL, Douady CJ, Andersson JO, Roger AJ. How big is the iceberg of which organellar genes in nuclear genomes are but the tip? Philos Trans R Soc Lond B Biol Sci 2003; 358:39-57; discussion 57-8. [PMID: 12594917 PMCID: PMC1693099 DOI: 10.1098/rstb.2002.1185] [Citation(s) in RCA: 121] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
As more and more complete bacterial and archaeal genome sequences become available, the role of lateral gene transfer (LGT) in shaping them becomes more and more clear. Over the long term, it may be the dominant force, affecting most genes in most prokaryotes. We review the history of LGT, suggesting reasons why its prevalence and impact were so long dismissed. We discuss various methods purporting to measure the extent of LGT, and evidence for and against the notion that there is a core of never-exchanged genes shared by all genomes, from which we can deduce the "true" organismal tree. We also consider evidence for, and implications of, LGT between prokaryotes and phagocytic eukaryotes.
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Affiliation(s)
- W F Doolittle
- Genome Atlantic, Dalhousie University, 5850 College Street, Halifax, Nova Scotia B3H 1X5, Canada.
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