1
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Ewerling A, May-Simera HL. Evolutionary trajectory for nuclear functions of ciliary transport complex proteins. Microbiol Mol Biol Rev 2024:e0000624. [PMID: 38995044 DOI: 10.1128/mmbr.00006-24] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/13/2024] Open
Abstract
SUMMARYCilia and the nucleus were two defining features of the last eukaryotic common ancestor. In early eukaryotic evolution, these structures evolved through the diversification of a common membrane-coating ancestor, the protocoatomer. While in cilia, the descendants of this protein complex evolved into parts of the intraflagellar transport complexes and BBSome, the nucleus gained its selectivity by recruiting protocoatomer-like proteins to the nuclear envelope to form the selective nuclear pore complexes. Recent studies show a growing number of proteins shared between the proteomes of the respective organelles, and it is currently unknown how ciliary transport proteins could acquire nuclear functions and vice versa. The nuclear functions of ciliary proteins are still observable today and remain relevant for the understanding of the disease mechanisms behind ciliopathies. In this work, we review the evolutionary history of cilia and nucleus and their respective defining proteins and integrate current knowledge into theories for early eukaryotic evolution. We postulate a scenario where both compartments co-evolved and that fits current models of eukaryotic evolution, explaining how ciliary proteins and nucleoporins acquired their dual functions.
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Affiliation(s)
- Alexander Ewerling
- Faculty of Biology, Institute of Molecular Physiology, Johannes Gutenberg-University, Mainz, Germany
| | - Helen Louise May-Simera
- Faculty of Biology, Institute of Molecular Physiology, Johannes Gutenberg-University, Mainz, Germany
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2
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Greenwold MJ, Merritt K, Richardson TL, Dudycha JL. A three-genome ultraconserved element phylogeny of cryptophytes. Protist 2023; 174:125994. [PMID: 37935085 DOI: 10.1016/j.protis.2023.125994] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2023] [Revised: 09/18/2023] [Accepted: 10/31/2023] [Indexed: 11/09/2023]
Abstract
Cryptophytes are single celled protists found in all aquatic environments. They are composed of a heterotrophic genus, Goniomonas, and a largely autotrophic group comprising many genera. Cryptophytes evolved through secondary endosymbiosis between a host eukaryotic heterotroph and a symbiont red alga. This merger resulted in a four-genome system that includes the nuclear and mitochondrial genomes from the host and a second nuclear genome (nucleomorph) and plastid genome inherited from the symbiont. Here, we make use of different genomes (with potentially distinct evolutionary histories) to perform a phylogenomic study of the early history of cryptophytes. Using ultraconserved elements from the host nuclear genome and symbiont nucleomorph and plastid genomes, we produce a three-genome phylogeny of 91 strains of cryptophytes. Our phylogenetic analyses find that that there are three major cryptophyte clades: Clade 1 comprises Chroomonas and Hemiselmis species, Clade 2, a taxonomically rich clade, comprises at least twelve genera, and Clade 3, comprises the heterotrophic Goniomonas species. Each of these major clades include both freshwater and marine species, but subclades within these clades differ in degrees of niche conservatism. Finally, we discuss priorities for taxonomic revision to Cryptophyceae based on previous studies and in light of these phylogenomic analyses.
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Affiliation(s)
- Matthew J Greenwold
- Biology Department, University of Texas at Tyler, 3900 University Blvd., Tyler, TX, 75799, USA.
| | - Kristiaän Merritt
- Department of Biological Sciences, University of South Carolina, 715 Sumter St., Columbia, SC 29208, USA
| | - Tammi L Richardson
- Department of Biological Sciences, University of South Carolina, 715 Sumter St., Columbia, SC 29208, USA; School of the Earth, Ocean, and Environment, University of South Carolina, 715 Sumter St., Columbia, SC 29208, USA
| | - Jeffry L Dudycha
- Department of Biological Sciences, University of South Carolina, 715 Sumter St., Columbia, SC 29208, USA
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3
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Spafford JD. A governance of ion selectivity based on the occupancy of the "beacon" in one- and four-domain calcium and sodium channels. Channels (Austin) 2023; 17:2191773. [PMID: 37075164 PMCID: PMC10120453 DOI: 10.1080/19336950.2023.2191773] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/21/2023] Open
Abstract
One of nature's exceptions was discovered when a Cav3 T-type channel was observed to switch phenotype from a calcium channel into a sodium channel by neutralizing an aspartate residue in the high field strength (HFS) +1 position within the ion selectivity filter. The HFS+1 site is dubbed a "beacon" for its location at the entryway just above the constricted, minimum radius of the HFS site's electronegative ring. A classification is proposed based on the occupancy of the HFS+1 "beacon" which correlates with the calcium- or sodium-selectivity phenotype. If the beacon is a glycine, or neutral, non-glycine residue, then the cation channel is calcium-selective or sodium-permeable, respectively (Class I). Occupancy of a beacon aspartate are calcium-selective channels (Class II) or possessing a strong calcium block (Class III). A residue lacking in position of the sequence alignment for the beacon are sodium channels (Class IV). The extent to which animal channels are sodium-selective is dictated in the occupancy of the HFS site with a lysine residue (Class III/IV). Governance involving the beacon solves the quandary the HFS site as a basis for ion selectivity, where an electronegative ring of glutamates at the HFS site generates a sodium-selective channel in one-domain channels but generates a calcium-selective channel in four-domain channels. Discovery of a splice variant in an exceptional channel revealed nature's exploits, highlighting the "beacon" as a principal determinant for calcium and sodium selectivity, encompassing known ion channels composed of one and four domains, from bacteria to animals.
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Affiliation(s)
- J David Spafford
- Department of Biology, University of Waterloo, Waterloo, Ontario, Canada
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4
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Eukaryotic evolution: Deep phylogeny does not imply morphological novelty. Curr Biol 2023; 33:R112-R114. [PMID: 36750023 DOI: 10.1016/j.cub.2022.12.016] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/09/2023]
Abstract
Eukaryotic diversity is often depicted as a molecular phylogenetic tree consisting of a few supergroups that originated over a billion years ago. A new study reveals an ancient group of tiny phagotrophic flagellates that reinforces inferences about early evolutionary history.
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5
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Single cell genomics reveals plastid-lacking Picozoa are close relatives of red algae. Nat Commun 2021; 12:6651. [PMID: 34789758 PMCID: PMC8599508 DOI: 10.1038/s41467-021-26918-0] [Citation(s) in RCA: 28] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2021] [Accepted: 10/29/2021] [Indexed: 12/27/2022] Open
Abstract
The endosymbiotic origin of plastids from cyanobacteria gave eukaryotes photosynthetic capabilities and launched the diversification of countless forms of algae. These primary plastids are found in members of the eukaryotic supergroup Archaeplastida. All known archaeplastids still retain some form of primary plastids, which are widely assumed to have a single origin. Here, we use single-cell genomics from natural samples combined with phylogenomics to infer the evolutionary origin of the phylum Picozoa, a globally distributed but seemingly rare group of marine microbial heterotrophic eukaryotes. Strikingly, the analysis of 43 single-cell genomes shows that Picozoa belong to Archaeplastida, specifically related to red algae and the phagotrophic rhodelphids. These picozoan genomes support the hypothesis that Picozoa lack a plastid, and further reveal no evidence of an early cryptic endosymbiosis with cyanobacteria. These findings change our understanding of plastid evolution as they either represent the first complete plastid loss in a free-living taxon, or indicate that red algae and rhodelphids obtained their plastids independently of other archaeplastids.
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6
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Aponte A, Gyaltshen Y, Burns JA, Heiss AA, Kim E, Warring SD. The Bacterial Diversity Lurking in Protist Cell Cultures. AMERICAN MUSEUM NOVITATES 2021. [DOI: 10.1206/3975.1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
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7
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Abstract
The origin of plastids (chloroplasts) by endosymbiosis stands as one of the most important events in the history of eukaryotic life. The genetic, biochemical, and cell biological integration of a cyanobacterial endosymbiont into a heterotrophic host eukaryote approximately a billion years ago paved the way for the evolution of diverse algal groups in a wide range of aquatic and, eventually, terrestrial environments. Plastids have on multiple occasions also moved horizontally from eukaryote to eukaryote by secondary and tertiary endosymbiotic events. The overall picture of extant photosynthetic diversity can best be described as “patchy”: Plastid-bearing lineages are spread far and wide across the eukaryotic tree of life, nested within heterotrophic groups. The algae do not constitute a monophyletic entity, and understanding how, and how often, plastids have moved from branch to branch on the eukaryotic tree remains one of the most fundamental unsolved problems in the field of cell evolution. In this review, we provide an overview of recent advances in our understanding of the origin and spread of plastids from the perspective of comparative genomics. Recent years have seen significant improvements in genomic sampling from photosynthetic and nonphotosynthetic lineages, both of which have added important pieces to the puzzle of plastid evolution. Comparative genomics has also allowed us to better understand how endosymbionts become organelles.
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Affiliation(s)
- Shannon J Sibbald
- Department of Biochemistry & Molecular Biology, Dalhousie University, Halifax, Nova Scotia, Canada.,Centre for Comparative Genomics and Evolutionary Bioinformatics, Dalhousie University, Halifax, Nova Scotia, Canada
| | - John M Archibald
- Department of Biochemistry & Molecular Biology, Dalhousie University, Halifax, Nova Scotia, Canada.,Centre for Comparative Genomics and Evolutionary Bioinformatics, Dalhousie University, Halifax, Nova Scotia, Canada
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8
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Irisarri I, Strassert JFH, Burki F. Phylogenomic Insights into the Origin of Primary Plastids. Syst Biol 2021; 71:105-120. [PMID: 33988690 DOI: 10.1093/sysbio/syab036] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2020] [Revised: 05/07/2021] [Accepted: 05/10/2021] [Indexed: 11/13/2022] Open
Abstract
The origin of plastids was a major evolutionary event that paved the way for an astonishing diversification of photosynthetic eukaryotes. Plastids originated by endosymbiosis between a heterotrophic eukaryotic host and cyanobacteria, presumably in a common ancestor of the primary photosynthetic eukaryotes (Archaeplastida). A single origin of primary plastids is well supported by plastid evidence but not by nuclear phylogenomic analyses, which have consistently failed to recover the monophyly of Archaeplastida hosts. Importantly, plastid monophyly and non-monophyletic hosts could be explained under scenarios of independent or serial eukaryote-to-eukaryote endosymbioses. Here, we assessed the strength of the signal for the monophyly of Archaeplastida hosts in four available phylogenomic datasets. The effect of phylogenetic methodology, data quality, alignment trimming strategy, gene and taxon sampling, and the presence of outlier genes were investigated. Our analyses revealed a lack of support for host monophyly in the shorter individual datasets. However, when analyzed together under rigorous data curation and complex mixture models, the combined nuclear datasets supported the monophyly of primary photosynthetic eukaryotes (Archaeplastida) and revealed a putative association with plastid-lacking Picozoa. This study represents an important step towards better understanding deep eukaryotic evolution and the origin of plastids.
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Affiliation(s)
- Iker Irisarri
- Department of Organismal Biology (Systematic Biology), Uppsala University, Norbyv. 18D, 75236 Uppsala, Sweden.,Department of Biodiversity and Evolutionary Biology, Museo Nacional de Ciencias Naturales, José Gutiérrez Abascal 2, 28006 Madrid, Spain
| | - Jürgen F H Strassert
- Department of Organismal Biology (Systematic Biology), Uppsala University, Norbyv. 18D, 75236 Uppsala, Sweden.,Department of Ecosystem Research, Leibniz Institute of Freshwater Ecology and Inland Fisheries, Müggelseedamm 301, 12587 Berlin, Germany
| | - Fabien Burki
- Department of Organismal Biology (Systematic Biology), Uppsala University, Norbyv. 18D, 75236 Uppsala, Sweden.,Science For Life Laboratory, Uppsala University, 75236 Sweden
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9
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Tanifuji G, Kamikawa R, Moore CE, Mills T, Onodera NT, Kashiyama Y, Archibald JM, Inagaki Y, Hashimoto T. Comparative Plastid Genomics of Cryptomonas Species Reveals Fine-Scale Genomic Responses to Loss of Photosynthesis. Genome Biol Evol 2020; 12:3926-3937. [PMID: 31922581 PMCID: PMC7058160 DOI: 10.1093/gbe/evaa001] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/04/2020] [Indexed: 01/20/2023] Open
Abstract
Loss of photosynthesis is a recurring theme in eukaryotic evolution. In organisms that have lost the ability to photosynthesize, nonphotosynthetic plastids are retained because they play essential roles in processes other than photosynthesis. The unicellular algal genus Cryptomonas contains both photosynthetic and nonphotosynthetic members, the latter having lost the ability to photosynthesize on at least three separate occasions. To elucidate the evolutionary processes underlying the loss of photosynthesis, we sequenced the plastid genomes of two nonphotosynthetic strains, Cryptomonas sp. CCAC1634B and SAG977-2f, as well as the genome of the phototroph Cryptomonas curvata CCAP979/52. These three genome sequences were compared with the previously sequenced plastid genome of the nonphotosynthetic species Cryptomonas paramecium CCAP977/2a as well as photosynthetic members of the Cryptomonadales, including C. curvata FBCC300012D. Intraspecies comparison between the two C. curvata strains showed that although their genome structures are stable, the substitution rates of their genes are relatively high. Although most photosynthesis-related genes, such as the psa and psb gene families, were found to have disappeared from the nonphotosynthetic strains, at least ten pseudogenes are retained in SAG977-2f. Although gene order is roughly shared among the plastid genomes of photosynthetic Cryptomonadales, genome rearrangements are seen more frequently in the smaller genomes of the nonphotosynthetic strains. Intriguingly, the light-independent protochlorophyllide reductase comprising chlB, L, and N is retained in nonphotosynthetic SAG977-2f and CCAC1634B. On the other hand, whereas CCAP977/2a retains ribulose-1,5-bisphosphate carboxylase/oxygenase-related genes, including rbcL, rbcS, and cbbX, the plastid genomes of the other two nonphotosynthetic strains have lost the ribulose-1,5-bisphosphate carboxylase/oxygenase protein-coding genes.
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Affiliation(s)
- Goro Tanifuji
- Department of Zoology, National Museum of Nature and Science, Ibaraki, Japan
| | - Ryoma Kamikawa
- Graduate School of Human and Environmental Studies, Kyoto University, Kyoto, Japan
| | - Christa E Moore
- Department of Biochemistry and Molecular Biology, Dalhousie University, Halifax, Nova Scotia, Canada
| | - Tyler Mills
- Department of Biochemistry and Molecular Biology, Dalhousie University, Halifax, Nova Scotia, Canada
| | - Naoko T Onodera
- Department of Biochemistry and Molecular Biology, Dalhousie University, Halifax, Nova Scotia, Canada
| | - Yuichiro Kashiyama
- Department of Applied Chemistry and Food Science, Fukui University of Technology, Fukui, Japan
| | - John M Archibald
- Department of Biochemistry and Molecular Biology, Dalhousie University, Halifax, Nova Scotia, Canada
| | - Yuji Inagaki
- Center for Computational Sciences, University of Tsukuba, Ibaraki, Japan.,Graduate School of Life and Environmental Sciences, University of Tsukuba, Ibaraki, Japan
| | - Tetsuo Hashimoto
- Graduate School of Life and Environmental Sciences, University of Tsukuba, Ibaraki, Japan
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10
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Heiss AA, Warring SD, Lukacs K, Favate J, Yang A, Gyaltshen Y, Filardi C, Simpson AGB, Kim E. Description of Imasa heleensis, gen. nov., sp. nov. (Imasidae, fam. nov.), a Deep-Branching Marine Malawimonad and Possible Key Taxon in Understanding Early Eukaryotic Evolution. J Eukaryot Microbiol 2020; 68:e12837. [PMID: 33274482 DOI: 10.1111/jeu.12837] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2020] [Revised: 09/23/2020] [Accepted: 11/13/2020] [Indexed: 12/23/2022]
Abstract
Malawimonadida is a deep-level (arguably "kingdom-scale") lineage of eukaryotes whose phylogenetic affinities are uncertain but of great evolutionary interest, as the group is suspected to branch close to the root of the tree of eukaryotes. Part of the difficulty in placing Malawimonadida phylogenetically is its tiny circumscription: at present, it comprises only two described and one cultured but undescribed species, all of them are freshwater suspension-feeding nanoflagellates. In this study, we cultivated and characterised Imasa heleensis gen. nov., sp. nov. (Imasidae fam. nov.), the first marine malawimonad to be described. Light and electron microscopy observations show that Imasa is largely similar to other malawimonads, but more frequently adheres to the substrate, often by means of a pliable posterior extension. Phylogenetic analyses based on two ribosomal RNA genes and four translated protein-coding genes using three different taxon sets place Imasa as sister to the three freshwater malawimonad strains with strong support. Imasa's mitochondrial genome is circular-mapping and shows a similar gene complement to other known malawimonads. We conclude that Imasa represents an important expansion of the range of taxa available for future evolutionary study.
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Affiliation(s)
- Aaron A Heiss
- Department of Invertebrate Zoology and Sackler Institute for Comparative Genomics, American Museum of Natural History, Central Park West at 79th Street, New York City, New York, 10024, USA
| | - Sally D Warring
- Department of Invertebrate Zoology and Sackler Institute for Comparative Genomics, American Museum of Natural History, Central Park West at 79th Street, New York City, New York, 10024, USA
| | - Kaleigh Lukacs
- Department of Invertebrate Zoology and Sackler Institute for Comparative Genomics, American Museum of Natural History, Central Park West at 79th Street, New York City, New York, 10024, USA
| | - John Favate
- Department of Invertebrate Zoology and Sackler Institute for Comparative Genomics, American Museum of Natural History, Central Park West at 79th Street, New York City, New York, 10024, USA
| | - Ashley Yang
- Department of Invertebrate Zoology and Sackler Institute for Comparative Genomics, American Museum of Natural History, Central Park West at 79th Street, New York City, New York, 10024, USA
| | - Yangtsho Gyaltshen
- Department of Invertebrate Zoology and Sackler Institute for Comparative Genomics, American Museum of Natural History, Central Park West at 79th Street, New York City, New York, 10024, USA
| | | | - Alastair G B Simpson
- Department of Biology and Centre for Comparative Genomics and Evolutionary Bioinformatics, Dalhousie University, 1355 Oxford St, Halifax, Nova Scotia, B3H 4R2, Canada
| | - Eunsoo Kim
- Department of Invertebrate Zoology and Sackler Institute for Comparative Genomics, American Museum of Natural History, Central Park West at 79th Street, New York City, New York, 10024, USA
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11
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Yazaki E, Kume K, Shiratori T, Eglit Y, Tanifuji G, Harada R, Simpson AGB, Ishida KI, Hashimoto T, Inagaki Y. Barthelonids represent a deep-branching metamonad clade with mitochondrion-related organelles predicted to generate no ATP. Proc Biol Sci 2020; 287:20201538. [PMID: 32873198 PMCID: PMC7542792 DOI: 10.1098/rspb.2020.1538] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
We here report the phylogenetic position of barthelonids, small anaerobic flagellates previously examined using light microscopy alone. Barthelona spp. were isolated from geographically distinct regions and we established five laboratory strains. Transcriptomic data generated from one Barthelona strain (PAP020) were used for large-scale, multi-gene phylogenetic (phylogenomic) analyses. Our analyses robustly placed strain PAP020 at the base of the Fornicata clade, indicating that barthelonids represent a deep-branching metamonad clade. Considering the anaerobic/microaerophilic nature of barthelonids and preliminary electron microscopy observations on strain PAP020, we suspected that barthelonids possess functionally and structurally reduced mitochondria (i.e. mitochondrion-related organelles or MROs). The metabolic pathways localized in the MRO of strain PAP020 were predicted based on its transcriptomic data and compared with those in the MROs of fornicates. We here propose that strain PAP020 is incapable of generating ATP in the MRO, as no mitochondrial/MRO enzymes involved in substrate-level phosphorylation were detected. Instead, we detected a putative cytosolic ATP-generating enzyme (acetyl-CoA synthetase), suggesting that strain PAP020 depends on ATP generated in the cytosol. We propose two separate losses of substrate-level phosphorylation from the MRO in the clade containing barthelonids and (other) fornicates.
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Affiliation(s)
- Euki Yazaki
- Interdisciplinary Theoretical and Mathematical Sciences (iTHEMS), RIKEN, Wako, Saitama, Japan
| | - Keitaro Kume
- Faculty of Medicine, University of Tsukuba, Tsukuba, Ibaraki, Japan
| | - Takashi Shiratori
- Faculty of Life and Environmental Sciences, University of Tsukuba, Tsukuba, Ibaraki, Japan.,Graduate School of Life and Environmental Sciences, University of Tsukuba, Tsukuba, Ibaraki, Japan
| | - Yana Eglit
- Department of Biology, Dalhousie University, Halifax, Nova Scotia, Canada.,Centre for Comparative Genomics and Evolutionary Bioinformatics, Dalhousie University, Halifax, Nova Scotia, Canada
| | - Goro Tanifuji
- Department of Zoology, National Museum of Nature and Science, Ibaraki, Japan
| | - Ryo Harada
- Graduate School of Life and Environmental Sciences, University of Tsukuba, Tsukuba, Ibaraki, Japan
| | - Alastair G B Simpson
- Department of Biology, Dalhousie University, Halifax, Nova Scotia, Canada.,Centre for Comparative Genomics and Evolutionary Bioinformatics, Dalhousie University, Halifax, Nova Scotia, Canada
| | - Ken-Ichiro Ishida
- Faculty of Life and Environmental Sciences, University of Tsukuba, Tsukuba, Ibaraki, Japan.,Graduate School of Life and Environmental Sciences, University of Tsukuba, Tsukuba, Ibaraki, Japan
| | - Tetsuo Hashimoto
- Faculty of Life and Environmental Sciences, University of Tsukuba, Tsukuba, Ibaraki, Japan.,Graduate School of Life and Environmental Sciences, University of Tsukuba, Tsukuba, Ibaraki, Japan
| | - Yuji Inagaki
- Graduate School of Life and Environmental Sciences, University of Tsukuba, Tsukuba, Ibaraki, Japan.,Center for Computational Sciences, University of Tsukuba, Tsukuba, Ibaraki, Japan
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12
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Abstract
Developing a detailed understanding of how all known forms of life are related to one another in the tree of life has been a major preoccupation of biology since the idea of tree-like evolution first took hold. Since most life is microbial, our intuitive use of morphological comparisons to infer relatedness only goes so far, and molecular sequence data, most recently from genomes and transcriptomes, has been the primary means to infer these relationships. For prokaryotes this presented new challenges, since the degree of horizontal gene transfer led some to question the tree-like depiction of evolution altogether. Most eukaryotes are also microbial, but in contrast to prokaryotic life, the application of large-scale molecular data to the tree of eukaryotes has largely been a constructive process, leading to a small number of very diverse lineages, or 'supergroups'. The tree is not completely resolved, and contentious problems remain, but many well-established supergroups now encompass much more diversity than the traditional kingdoms. Some of the most exciting recent developments come from the discovery of branches in the tree that we previously had no inkling even existed, many of which are of great ecological or evolutionary interest. These new branches highlight the need for more exploration, by high-throughput molecular surveys, but also more traditional means of observations and cultivation.
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Affiliation(s)
- Patrick J Keeling
- Department of Botany, University of British Columbia, Vancouver V6T 1Z4, British Columbia, Canada.
| | - Fabien Burki
- Department of Organismal Biology, Program in Systematic Biology, Uppsala University, Uppsala, Sweden; Science for Life Laboratory, Uppsala University, Uppsala, Sweden
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13
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Nishimura Y, Kume K, Sonehara K, Tanifuji G, Shiratori T, Ishida KI, Hashimoto T, Inagaki Y, Ohkuma M. Mitochondrial Genomes of Hemiarma marina and Leucocryptos marina Revised the Evolution of Cytochrome c Maturation in Cryptista. Front Ecol Evol 2020. [DOI: 10.3389/fevo.2020.00140] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
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14
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Palmgren M, Sørensen DM, Hallström BM, Säll T, Broberg K. Evolution of P2A and P5A ATPases: ancient gene duplications and the red algal connection to green plants revisited. PHYSIOLOGIA PLANTARUM 2020; 168:630-647. [PMID: 31268560 PMCID: PMC7065118 DOI: 10.1111/ppl.13008] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/30/2019] [Revised: 06/20/2019] [Accepted: 06/27/2019] [Indexed: 05/14/2023]
Abstract
In a search for slowly evolving nuclear genes that may cast light on the deep evolution of plants, we carried out phylogenetic analyses of two well-characterized subfamilies of P-type pumps (P2A and P5A ATPases) from representative branches of the eukaryotic tree of life. Both P-type ATPase genes were duplicated very early in eukaryotic evolution and before the divergence of the present eukaryotic supergroups. Synapomorphies identified in the sequences provide evidence that green plants and red algae are more distantly related than are green plants and eukaryotic supergroups in which secondary or tertiary plastids are common, such as several groups belonging to the clade that includes Stramenopiles, Alveolata, Rhizaria, Cryptophyta and Haptophyta (SAR). We propose that red algae branched off soon after the first photosynthesizing eukaryote had acquired a primary plastid, while in another lineage that led to SAR, the primary plastid was lost but, in some cases, regained as a secondary or tertiary plastid.
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Affiliation(s)
- Michael Palmgren
- Department of Plant and Environmental SciencesUniversity of CopenhagenCopenhagenDenmark
- Institute of Environmental MedicineKarolinska InstitutetStockholmSweden
| | | | - Björn M. Hallström
- Science for Life LaboratoryKTH – Royal Institute of TechnologyStockholmSweden
| | | | - Karin Broberg
- Institute of Environmental MedicineKarolinska InstitutetStockholmSweden
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15
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Substrate specificity of plastid phosphate transporters in a non-photosynthetic diatom and its implication in evolution of red alga-derived complex plastids. Sci Rep 2020; 10:1167. [PMID: 31980711 PMCID: PMC6981301 DOI: 10.1038/s41598-020-58082-8] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2019] [Accepted: 01/07/2020] [Indexed: 02/07/2023] Open
Abstract
The triose phosphate transporter (TPT) is one of the prerequisites to exchange metabolites between the cytosol and plastids. In this study, we demonstrated that the four plastid TPT homologues in the non-photosynthetic diatom Nitzschia sp. NIES-3581 were highly likely integrated into plastid envelope membranes similar to counterparts in the model photosynthetic diatom Phaeodactylum tricornutum, in terms of target membranes and C-terminal orientations. Three of the four Nitzschia TPT homologues are capable of transporting various metabolites into proteo-liposomes including triose phosphates (TPs) and phosphoenolpyruvate (PEP), the transport substrates sufficient to support the metabolic pathways retained in the non-photosynthetic diatom plastid. Phylogenetic analysis of TPTs and closely related transporter proteins indicated that diatoms and other algae with red alga-derived complex plastids possess only TPT homologues but lack homologues of the glucose 6-phosphate transporter (GPT), xylulose 5-phosphate transporter (XPT), and phosphoenolpyruvate transporter (PPT). Comparative sequence analysis suggests that many TPT homologues of red alga-derived complex plastids potentially have the ability to transport mainly TPs and PEP. TPTs transporting both TPs and PEP highly likely mediate a metabolic crosstalk between a red alga-derived complex plastid and the cytosol in photosynthetic and non-photosynthetic species, which explains the lack of PPTs in all the lineages with red alga-derived complex plastids. The PEP-transporting TPTs might have emerged in an early phase of endosymbiosis between a red alga and a eukaryote host, given the broad distribution of that type of transporters in all branches of red alga-derived complex plastid-bearing lineages, and have probably played a key role in the establishment and retention of a controllable, intracellular metabolic connection in those organisms.
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16
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Taxon-rich Multigene Phylogenetic Analyses Resolve the Phylogenetic Relationship Among Deep-branching Stramenopiles. Protist 2019; 170:125682. [DOI: 10.1016/j.protis.2019.125682] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2018] [Revised: 08/27/2019] [Accepted: 08/28/2019] [Indexed: 01/09/2023]
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17
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Burki F, Roger AJ, Brown MW, Simpson AGB. The New Tree of Eukaryotes. Trends Ecol Evol 2019; 35:43-55. [PMID: 31606140 DOI: 10.1016/j.tree.2019.08.008] [Citation(s) in RCA: 396] [Impact Index Per Article: 79.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2019] [Revised: 08/15/2019] [Accepted: 08/15/2019] [Indexed: 01/01/2023]
Abstract
For 15 years, the eukaryote Tree of Life (eToL) has been divided into five to eight major groupings, known as 'supergroups'. However, the tree has been profoundly rearranged during this time. The new eToL results from the widespread application of phylogenomics and numerous discoveries of major lineages of eukaryotes, mostly free-living heterotrophic protists. The evidence that supports the tree has transitioned from a synthesis of molecular phylogenetics and biological characters to purely molecular phylogenetics. Most current supergroups lack defining morphological or cell-biological characteristics, making the supergroup label even more arbitrary than before. Going forward, the combination of traditional culturing with maturing culture-free approaches and phylogenomics should accelerate the process of completing and resolving the eToL at its deepest levels.
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Affiliation(s)
- Fabien Burki
- Department of Organismal Biology, Program in Systematic Biology, Uppsala University, Uppsala, Sweden; Science for Life Laboratory, Uppsala University, Uppsala, Sweden.
| | - Andrew J Roger
- Department of Biochemistry and Molecular Biology, Dalhousie University, Halifax, NS, Canada; Centre for Comparative Genomics and Evolutionary Bioinformatics, Dalhousie University, Halifax, NS, Canada
| | - Matthew W Brown
- Department of Biological Sciences, Mississippi State University, Mississippi State, MS, USA; Institute for Genomics, Biocomputing, and Biotechnology, Mississippi State University, Mississippi State, MS, USA
| | - Alastair G B Simpson
- Centre for Comparative Genomics and Evolutionary Bioinformatics, Dalhousie University, Halifax, NS, Canada; Department of Biology, Dalhousie University, Halifax, NS, Canada.
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18
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Strassert JFH, Jamy M, Mylnikov AP, Tikhonenkov DV, Burki F. New Phylogenomic Analysis of the Enigmatic Phylum Telonemia Further Resolves the Eukaryote Tree of Life. Mol Biol Evol 2019; 36:757-765. [PMID: 30668767 PMCID: PMC6844682 DOI: 10.1093/molbev/msz012] [Citation(s) in RCA: 61] [Impact Index Per Article: 12.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
The resolution of the broad-scale tree of eukaryotes is constantly improving, but the evolutionary origin of several major groups remains unknown. Resolving the phylogenetic position of these “orphan” groups is important, especially those that originated early in evolution, because they represent missing evolutionary links between established groups. Telonemia is one such orphan taxon for which little is known. The group is composed of molecularly diverse biflagellated protists, often prevalent although not abundant in aquatic environments. Telonemia has been hypothesized to represent a deeply diverging eukaryotic phylum but no consensus exists as to where it is placed in the tree. Here, we established cultures and report the phylogenomic analyses of three new transcriptome data sets for divergent telonemid lineages. All our phylogenetic reconstructions, based on 248 genes and using site-heterogeneous mixture models, robustly resolve the evolutionary origin of Telonemia as sister to the Sar supergroup. This grouping remains well supported when as few as 60% of the genes are randomly subsampled, thus is not sensitive to the sets of genes used but requires a minimal alignment length to recover enough phylogenetic signal. Telonemia occupies a crucial position in the tree to examine the origin of Sar, one of the most lineage-rich eukaryote supergroups. We propose the moniker “TSAR” to accommodate this new mega-assemblage in the phylogeny of eukaryotes.
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Affiliation(s)
- Jürgen F H Strassert
- Department of Organismal Biology, Program in Systematic Biology, Uppsala University, Uppsala, Sweden
| | - Mahwash Jamy
- Department of Organismal Biology, Program in Systematic Biology, Uppsala University, Uppsala, Sweden
| | - Alexander P Mylnikov
- Institute for Biology of Inland Waters, Russian Academy of Sciences, Borok, Yaroslavl Region, Russia
| | - Denis V Tikhonenkov
- Institute for Biology of Inland Waters, Russian Academy of Sciences, Borok, Yaroslavl Region, Russia
| | - Fabien Burki
- Department of Organismal Biology, Program in Systematic Biology, Uppsala University, Uppsala, Sweden
- Science for Life Laboratory, Uppsala University, Uppsala, Sweden
- Corresponding author: E-mail:
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Figueroa-Martinez F, Jackson C, Reyes-Prieto A. Plastid Genomes from Diverse Glaucophyte Genera Reveal a Largely Conserved Gene Content and Limited Architectural Diversity. Genome Biol Evol 2019; 11:174-188. [PMID: 30534986 PMCID: PMC6330054 DOI: 10.1093/gbe/evy268] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 12/10/2018] [Indexed: 12/30/2022] Open
Abstract
Plastid genome (ptDNA) data of Glaucophyta have been limited for many years to the genus Cyanophora. Here, we sequenced the ptDNAs of Gloeochaete wittrockiana, Cyanoptyche gloeocystis, Glaucocystis incrassata, and Glaucocystis sp. BBH. The reported sequences are the first genome-scale plastid data available for these three poorly studied glaucophyte genera. Although the Glaucophyta plastids appear morphologically “ancestral,” they actually bear derived genomes not radically different from those of red algae or viridiplants. The glaucophyte plastid coding capacity is highly conserved (112 genes shared) and the architecture of the plastid chromosomes is relatively simple. Phylogenomic analyses recovered Glaucophyta as the earliest diverging Archaeplastida lineage, but the position of viridiplants as the first branching group was not rejected by the approximately unbiased test. Pairwise distances estimated from 19 different plastid genes revealed that the highest sequence divergence between glaucophyte genera is frequently higher than distances between species of different classes within red algae or viridiplants. Gene synteny and sequence similarity in the ptDNAs of the two Glaucocystis species analyzed is conserved. However, the ptDNA of Gla. incrassata contains a 7.9-kb insertion not detected in Glaucocystis sp. BBH. The insertion contains ten open reading frames that include four coding regions similar to bacterial serine recombinases (two open reading frames), DNA primases, and peptidoglycan aminohydrolases. These three enzymes, often encoded in bacterial plasmids and bacteriophage genomes, are known to participate in the mobilization and replication of DNA mobile elements. It is therefore plausible that the insertion in Gla. incrassata ptDNA is derived from a DNA mobile element.
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Affiliation(s)
- Francisco Figueroa-Martinez
- Department of Biology, University of New Brunswick, Fredericton, New Brunswick, Canada.,CONACyT-Universidad Autónoma Metropolitana Iztapalapa, Biotechnology Department, Mexico City, Mexico
| | - Christopher Jackson
- Department of Biology, University of New Brunswick, Fredericton, New Brunswick, Canada.,School of Biosciences, University of Melbourne, Melbourne, Australia
| | - Adrian Reyes-Prieto
- Department of Biology, University of New Brunswick, Fredericton, New Brunswick, Canada
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20
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Cenci U, Sibbald SJ, Curtis BA, Kamikawa R, Eme L, Moog D, Henrissat B, Maréchal E, Chabi M, Djemiel C, Roger AJ, Kim E, Archibald JM. Nuclear genome sequence of the plastid-lacking cryptomonad Goniomonas avonlea provides insights into the evolution of secondary plastids. BMC Biol 2018; 16:137. [PMID: 30482201 PMCID: PMC6260743 DOI: 10.1186/s12915-018-0593-5] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2018] [Accepted: 10/12/2018] [Indexed: 11/21/2022] Open
Abstract
Background The evolution of photosynthesis has been a major driver in eukaryotic diversification. Eukaryotes have acquired plastids (chloroplasts) either directly via the engulfment and integration of a photosynthetic cyanobacterium (primary endosymbiosis) or indirectly by engulfing a photosynthetic eukaryote (secondary or tertiary endosymbiosis). The timing and frequency of secondary endosymbiosis during eukaryotic evolution is currently unclear but may be resolved in part by studying cryptomonads, a group of single-celled eukaryotes comprised of both photosynthetic and non-photosynthetic species. While cryptomonads such as Guillardia theta harbor a red algal-derived plastid of secondary endosymbiotic origin, members of the sister group Goniomonadea lack plastids. Here, we present the genome of Goniomonas avonlea—the first for any goniomonad—to address whether Goniomonadea are ancestrally non-photosynthetic or whether they lost a plastid secondarily. Results We sequenced the nuclear and mitochondrial genomes of Goniomonas avonlea and carried out a comparative analysis of Go. avonlea, Gu. theta, and other cryptomonads. The Go. avonlea genome assembly is ~ 92 Mbp in size, with 33,470 predicted protein-coding genes. Interestingly, some metabolic pathways (e.g., fatty acid biosynthesis) predicted to occur in the plastid and periplastidal compartment of Gu. theta appear to operate in the cytoplasm of Go. avonlea, suggesting that metabolic redundancies were generated during the course of secondary plastid integration. Other cytosolic pathways found in Go. avonlea are not found in Gu. theta, suggesting secondary loss in Gu. theta and other plastid-bearing cryptomonads. Phylogenetic analyses revealed no evidence for algal endosymbiont-derived genes in the Go. avonlea genome. Phylogenomic analyses point to a specific relationship between Cryptista (to which cryptomonads belong) and Archaeplastida. Conclusion We found no convincing genomic or phylogenomic evidence that Go. avonlea evolved from a secondary red algal plastid-bearing ancestor, consistent with goniomonads being ancestrally non-photosynthetic eukaryotes. The Go. avonlea genome sheds light on the physiology of heterotrophic cryptomonads and serves as an important reference point for studying the metabolic “rewiring” that took place during secondary plastid integration in the ancestor of modern-day Cryptophyceae. Electronic supplementary material The online version of this article (10.1186/s12915-018-0593-5) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Ugo Cenci
- Department of Biochemistry and Molecular Biology, Dalhousie University, Halifax, Nova Scotia, B3H 4R2, Canada.,Centre for Comparative Genomics and Evolutionary Bioinformatics, Dalhousie University, Halifax, Nova Scotia, Canada
| | - Shannon J Sibbald
- Department of Biochemistry and Molecular Biology, Dalhousie University, Halifax, Nova Scotia, B3H 4R2, Canada.,Centre for Comparative Genomics and Evolutionary Bioinformatics, Dalhousie University, Halifax, Nova Scotia, Canada
| | - Bruce A Curtis
- Department of Biochemistry and Molecular Biology, Dalhousie University, Halifax, Nova Scotia, B3H 4R2, Canada.,Centre for Comparative Genomics and Evolutionary Bioinformatics, Dalhousie University, Halifax, Nova Scotia, Canada
| | - Ryoma Kamikawa
- Graduate School of Human and Environmental Studies, Kyoto University, Kyoto, Kyoto, 606-8501, Japan
| | - Laura Eme
- Department of Biochemistry and Molecular Biology, Dalhousie University, Halifax, Nova Scotia, B3H 4R2, Canada.,Centre for Comparative Genomics and Evolutionary Bioinformatics, Dalhousie University, Halifax, Nova Scotia, Canada.,Present address: Department of Cell and Molecular Biology, Science for Life Laboratory, Uppsala University, SE-75123, Uppsala, Sweden
| | - Daniel Moog
- Department of Biochemistry and Molecular Biology, Dalhousie University, Halifax, Nova Scotia, B3H 4R2, Canada.,Centre for Comparative Genomics and Evolutionary Bioinformatics, Dalhousie University, Halifax, Nova Scotia, Canada.,Present address: Laboratory for Cell Biology, Philipps University Marburg, Karl-von-Frisch-Str. 8, 35043, Marburg, Germany
| | - Bernard Henrissat
- Architecture et Fonction des Macromolécules Biologiques (AFMB), CNRS, Université Aix-Marseille, 163 Avenue de Luminy, 13288, Marseille, France.,INRA, USC 1408 AFMB, 13288, Marseille, France.,Department of Biological Sciences, King Abdulaziz University, Jeddah, 21589, Saudi Arabia
| | - Eric Maréchal
- Laboratoire de Physiologie Cellulaire et Végétale, CNRS, CEA, INRA, Université Grenoble Alpes, Institut de Biosciences et Biotechnologies de Grenoble, CEA-Grenoble, 17 rue des Martyrs, 38000, Grenoble, France
| | - Malika Chabi
- Present address: UMR 8576 - Unité de glycobiologie structurale et fonctionnelle, Université Lille 1, 59650, Villeneuve d'Ascq, France
| | - Christophe Djemiel
- Present address: UMR 8576 - Unité de glycobiologie structurale et fonctionnelle, Université Lille 1, 59650, Villeneuve d'Ascq, France
| | - Andrew J Roger
- Department of Biochemistry and Molecular Biology, Dalhousie University, Halifax, Nova Scotia, B3H 4R2, Canada.,Centre for Comparative Genomics and Evolutionary Bioinformatics, Dalhousie University, Halifax, Nova Scotia, Canada.,Canadian Institute for Advanced Research, Program in Integrated Microbial Biodiversity, Toronto, Ontario, Canada
| | - Eunsoo Kim
- Division of Invertebrate Zoology & Sackler Institute for Comparative Genomics, American Museum of Natural History, Central Park West at 79 Street, New York, NY, 10024, USA
| | - John M Archibald
- Department of Biochemistry and Molecular Biology, Dalhousie University, Halifax, Nova Scotia, B3H 4R2, Canada. .,Centre for Comparative Genomics and Evolutionary Bioinformatics, Dalhousie University, Halifax, Nova Scotia, Canada. .,Canadian Institute for Advanced Research, Program in Integrated Microbial Biodiversity, Toronto, Ontario, Canada.
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21
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Yabuki A, Gyaltshen Y, Heiss AA, Fujikura K, Kim E. Ophirina amphinema n. gen., n. sp., a New Deeply Branching Discobid with Phylogenetic Affinity to Jakobids. Sci Rep 2018; 8:16219. [PMID: 30385814 PMCID: PMC6212452 DOI: 10.1038/s41598-018-34504-6] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2018] [Accepted: 10/17/2018] [Indexed: 01/25/2023] Open
Abstract
We report a novel nanoflagellate, Ophirina amphinema n. gen. n. sp., isolated from a lagoon of the Solomon Islands. The flagellate displays ‘typical excavate’ morphological characteristics, such as the presence of a ventral feeding groove with vanes on the posterior flagellum. The cell is ca. 4 µm in length, bears two flagella, and has a single mitochondrion with flat to discoid cristae. The flagellate exists in two morphotypes: a suspension-feeder, which bears flagella that are about the length of the cell, and a swimmer, which has longer flagella. In a tree based on the analysis of 156 proteins, Ophirina is sister to jakobids, with moderate bootstrap support. Ophirina has some ultrastructural (e.g. B-fibre associated with the posterior basal body) and mtDNA (e.g. rpoA–D) features in common with jakobids. Yet, other morphological features, including the crista morphology and presence of two flagellar vanes, rather connect Ophirina to non-jakobid or non-discobid excavates. Ophirina amphinema has some unique features, such as an unusual segmented core structure within the basal bodies and a rightward-oriented dorsal fan. Thus, Ophirina represents a new deeply-branching member of Discoba, and its mosaic morphological characteristics may illuminate aspects of the ancestral eukaryotic cellular body plan.
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Affiliation(s)
- Akinori Yabuki
- Department of Marine Biodiversity Research, Japan Agency for Marine-Earth Science and Technology (JAMSTEC), Yokosuka, Japan.
| | - Yangtsho Gyaltshen
- Division of Invertebrate Zoology and Sackler Institute for Comparative Genomics, American Museum of Natural History, New York, USA
| | - Aaron A Heiss
- Division of Invertebrate Zoology and Sackler Institute for Comparative Genomics, American Museum of Natural History, New York, USA
| | - Katsunori Fujikura
- Department of Marine Biodiversity Research, Japan Agency for Marine-Earth Science and Technology (JAMSTEC), Yokosuka, Japan
| | - Eunsoo Kim
- Division of Invertebrate Zoology and Sackler Institute for Comparative Genomics, American Museum of Natural History, New York, USA.
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22
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Nowack ECM, Weber APM. Genomics-Informed Insights into Endosymbiotic Organelle Evolution in Photosynthetic Eukaryotes. ANNUAL REVIEW OF PLANT BIOLOGY 2018; 69:51-84. [PMID: 29489396 DOI: 10.1146/annurev-arplant-042817-040209] [Citation(s) in RCA: 42] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/09/2023]
Abstract
The conversion of free-living cyanobacteria to photosynthetic organelles of eukaryotic cells through endosymbiosis transformed the biosphere and eventually provided the basis for life on land. Despite the presumable advantage conferred by the acquisition of photoautotrophy through endosymbiosis, only two independent cases of primary endosymbiosis have been documented: one that gave rise to the Archaeplastida, and the other to photosynthetic species of the thecate, filose amoeba Paulinella. Here, we review recent genomics-informed insights into the primary endosymbiotic origins of cyanobacteria-derived organelles. Furthermore, we discuss the preconditions for the evolution of nitrogen-fixing organelles. Recent genomic data on previously undersampled cyanobacterial and protist taxa provide new clues to the origins of the host cell and endosymbiont, and proteomic approaches allow insights into the rearrangement of the endosymbiont proteome during organellogenesis. We conclude that in addition to endosymbiotic gene transfers, horizontal gene acquisitions from a broad variety of prokaryotic taxa were crucial to organelle evolution.
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Affiliation(s)
- Eva C M Nowack
- Microbial Symbiosis and Organelle Evolution Group, Biology Department, Heinrich Heine University, 40225 Düsseldorf, Germany;
| | - Andreas P M Weber
- Institute of Plant Biochemistry, Cluster of Excellence on Plant Science (CEPLAS), Heinrich Heine University, 40225 Düsseldorf, Germany;
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23
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Kim JI, Yoon HS, Yi G, Shin W, Archibald JM. Comparative mitochondrial genomics of cryptophyte algae: gene shuffling and dynamic mobile genetic elements. BMC Genomics 2018; 19:275. [PMID: 29678149 PMCID: PMC5910586 DOI: 10.1186/s12864-018-4626-9] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2017] [Accepted: 03/27/2018] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Cryptophytes are an ecologically important group of algae comprised of phototrophic, heterotrophic and osmotrophic species. This lineage is of great interest to evolutionary biologists because their plastids are of red algal secondary endosymbiotic origin. Cryptophytes have a clear phylogenetic affinity to heterotrophic eukaryotes and possess four genomes: host-derived nuclear and mitochondrial genomes, and plastid and nucleomorph genomes of endosymbiotic origin. RESULTS To gain insight into cryptophyte mitochondrial genome evolution, we sequenced the mitochondrial DNAs of five species and performed a comparative analysis of seven genomes from the following cryptophyte genera: Chroomonas, Cryptomonas, Hemiselmis, Proteomonas, Rhodomonas, Storeatula and Teleaulax. The mitochondrial genomes were similar in terms of their general architecture, gene content and presence of a large repeat region. However, gene order was poorly conserved. Characteristic features of cryptophyte mtDNAs included large syntenic clusters resembling α-proteobacterial operons that encode bacteria-like rRNAs, tRNAs, and ribosomal protein genes. The cryptophyte mitochondrial genomes retain almost all genes found in many other eukaryotes including the nad, sdh, cox, cob, and atp genes, with the exception of sdh2 and atp3. In addition, gene cluster analysis showed that cryptophytes possess a gene order closely resembling the jakobid flagellates Jakoba and Reclinomonas. Interestingly, the cox1 gene of R. salina, T. amphioxeia, and Storeatula species was found to contain group II introns encoding a reverse transcriptase protein, as did the cob gene of Storeatula species CCMP1868. CONCLUSIONS These newly sequenced genomes increase the breadth of data available from algae and will aid in the identification of general trends in mitochondrial genome evolution. While most of the genomes were highly conserved, extensive gene arrangements have shuffled gene order, perhaps due to genome rearrangements associated with hairpin-containing mobile genetic elements, tRNAs with palindromic sequences, and tandem repeat sequences. The cox1 and cob gene sequences suggest that introns have recently been acquired during cryptophyte evolution. Comparison of phylogenetic trees based on plastid and mitochondrial genome data sets underscore the different evolutionary histories of the host and endosymbiont components of present-day cryptophytes.
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Affiliation(s)
- Jong Im Kim
- Department of Biology, Chungnam National University, Daejeon, 34134, South Korea
| | - Hwan Su Yoon
- Department of Biological Sciences, Sungkyunkwan University, Suwon, 16419, South Korea
| | - Gangman Yi
- Department of Multimedia Engineering, Dongguk University, Seoul, 04620, South Korea
| | - Woongghi Shin
- Department of Biology, Chungnam National University, Daejeon, 34134, South Korea.
| | - John M Archibald
- Department of Biochemistry and Molecular Biology, Dalhousie University, Halifax, NS, B3H 4R2, Canada.
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24
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Záhonová K, Petrželková R, Valach M, Yazaki E, Tikhonenkov DV, Butenko A, Janouškovec J, Hrdá Š, Klimeš V, Burger G, Inagaki Y, Keeling PJ, Hampl V, Flegontov P, Yurchenko V, Eliáš M. Extensive molecular tinkering in the evolution of the membrane attachment mode of the Rheb GTPase. Sci Rep 2018; 8:5239. [PMID: 29588502 PMCID: PMC5869587 DOI: 10.1038/s41598-018-23575-0] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2017] [Accepted: 03/15/2018] [Indexed: 02/07/2023] Open
Abstract
Rheb is a conserved and widespread Ras-like GTPase involved in cell growth regulation mediated by the (m)TORC1 kinase complex and implicated in tumourigenesis in humans. Rheb function depends on its association with membranes via prenylated C-terminus, a mechanism shared with many other eukaryotic GTPases. Strikingly, our analysis of a phylogenetically rich sample of Rheb sequences revealed that in multiple lineages this canonical and ancestral membrane attachment mode has been variously altered. The modifications include: (1) accretion to the N-terminus of two different phosphatidylinositol 3-phosphate-binding domains, PX in Cryptista (the fusion being the first proposed synapomorphy of this clade), and FYVE in Euglenozoa and the related undescribed flagellate SRT308; (2) acquisition of lipidic modifications of the N-terminal region, namely myristoylation and/or S-palmitoylation in seven different protist lineages; (3) acquisition of S-palmitoylation in the hypervariable C-terminal region of Rheb in apusomonads, convergently to some other Ras family proteins; (4) replacement of the C-terminal prenylation motif with four transmembrane segments in a novel Rheb paralog in the SAR clade; (5) loss of an evident C-terminal membrane attachment mechanism in Tremellomycetes and some Rheb paralogs of Euglenozoa. Rheb evolution is thus surprisingly dynamic and presents a spectacular example of molecular tinkering.
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Affiliation(s)
- Kristína Záhonová
- Department of Biology and Ecology & Institute of Environmental Technologies, Faculty of Science, University of Ostrava, Ostrava, Czech Republic
| | - Romana Petrželková
- Department of Biology and Ecology & Institute of Environmental Technologies, Faculty of Science, University of Ostrava, Ostrava, Czech Republic
| | - Matus Valach
- Department of Biochemistry and Robert-Cedergren Centre for Bioinformatics and Genomics, Université de Montréal, Montreal, Canada
| | - Euki Yazaki
- Institute for Biological Sciences, University of Tsukuba, Tsukuba, Japan
| | - Denis V Tikhonenkov
- Laboratory of Microbiology, Papanin Institute for Biology of Inland Waters, Russian Academy of Sciences, Borok, Russia
| | - Anzhelika Butenko
- Department of Biology and Ecology & Institute of Environmental Technologies, Faculty of Science, University of Ostrava, Ostrava, Czech Republic
| | - Jan Janouškovec
- Department of Genetics, Evolution and Environment, University College London, London, United Kingdom
| | - Štěpánka Hrdá
- Department of Parasitology, Faculty of Science, Charles University, Prague, Czech Republic
| | - Vladimír Klimeš
- Department of Biology and Ecology & Institute of Environmental Technologies, Faculty of Science, University of Ostrava, Ostrava, Czech Republic
| | - Gertraud Burger
- Department of Biochemistry and Robert-Cedergren Centre for Bioinformatics and Genomics, Université de Montréal, Montreal, Canada
| | - Yuji Inagaki
- Center for Computational Sciences, University of Tsukuba, Tsukuba, Japan
| | - Patrick J Keeling
- Department of Botany, University of British Columbia, Vancouver, Canada
| | - Vladimír Hampl
- Department of Parasitology, Faculty of Science, Charles University, Prague, Czech Republic
| | - Pavel Flegontov
- Department of Biology and Ecology & Institute of Environmental Technologies, Faculty of Science, University of Ostrava, Ostrava, Czech Republic
| | - Vyacheslav Yurchenko
- Department of Biology and Ecology & Institute of Environmental Technologies, Faculty of Science, University of Ostrava, Ostrava, Czech Republic
| | - Marek Eliáš
- Department of Biology and Ecology & Institute of Environmental Technologies, Faculty of Science, University of Ostrava, Ostrava, Czech Republic.
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25
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Janouškovec J, Tikhonenkov DV, Burki F, Howe AT, Rohwer FL, Mylnikov AP, Keeling PJ. A New Lineage of Eukaryotes Illuminates Early Mitochondrial Genome Reduction. Curr Biol 2017; 27:3717-3724.e5. [PMID: 29174886 DOI: 10.1016/j.cub.2017.10.051] [Citation(s) in RCA: 76] [Impact Index Per Article: 10.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2017] [Revised: 10/10/2017] [Accepted: 10/19/2017] [Indexed: 11/26/2022]
Abstract
The origin of eukaryotic cells represents a key transition in cellular evolution and is closely tied to outstanding questions about mitochondrial endosymbiosis [1, 2]. For example, gene-rich mitochondrial genomes are thought to be indicative of an ancient divergence, but this relies on unexamined assumptions about endosymbiont-to-host gene transfer [3-5]. Here, we characterize Ancoracysta twista, a new predatory flagellate that is not closely related to any known lineage in 201-protein phylogenomic trees and has a unique morphology, including a novel type of extrusome (ancoracyst). The Ancoracysta mitochondrion has a gene-rich genome with a coding capacity exceeding that of all other eukaryotes except the distantly related jakobids and Diphylleia, and it uniquely possesses heterologous, nucleus-, and mitochondrion-encoded cytochrome c maturase systems. To comprehensively examine mitochondrial genome reduction, we also assembled mitochondrial genomes from picozoans and colponemids and re-annotated existing mitochondrial genomes using hidden Markov model gene profiles. This revealed over a dozen previously overlooked mitochondrial genes at the level of eukaryotic supergroups. Analysis of trends over evolutionary time demonstrates that gene transfer to the nucleus was non-linear, that it occurred in waves of exponential decrease, and that much of it took place comparatively early, massively independently, and with lineage-specific rates. This process has led to differential gene retention, suggesting that gene-rich mitochondrial genomes are not a product of their early divergence. Parallel transfer of mitochondrial genes and their functional replacement by new nuclear factors are important in models for the origin of eukaryotes, especially as major gaps in our knowledge of eukaryotic diversity at the deepest level remain unfilled.
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Affiliation(s)
- Jan Janouškovec
- University College London, Department of Genetics, Evolution and Environment, London, UK; San Diego State University, Biology Department, San Diego, CA, USA; University of British Columbia, Botany Department, Vancouver, BC, Canada.
| | - Denis V Tikhonenkov
- University of British Columbia, Botany Department, Vancouver, BC, Canada; Institute for Biology of Inland Waters, Russian Academy of Sciences, Borok, Russia.
| | - Fabien Burki
- University of British Columbia, Botany Department, Vancouver, BC, Canada; Science for Life Laboratory, Program in Systematic Biology, Uppsala University, Uppsala, Sweden
| | - Alexis T Howe
- University of British Columbia, Botany Department, Vancouver, BC, Canada
| | - Forest L Rohwer
- San Diego State University, Biology Department, San Diego, CA, USA
| | - Alexander P Mylnikov
- Institute for Biology of Inland Waters, Russian Academy of Sciences, Borok, Russia
| | - Patrick J Keeling
- University of British Columbia, Botany Department, Vancouver, BC, Canada.
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Dorrell RG, Gile G, McCallum G, Méheust R, Bapteste EP, Klinger CM, Brillet-Guéguen L, Freeman KD, Richter DJ, Bowler C. Chimeric origins of ochrophytes and haptophytes revealed through an ancient plastid proteome. eLife 2017; 6. [PMID: 28498102 PMCID: PMC5462543 DOI: 10.7554/elife.23717] [Citation(s) in RCA: 99] [Impact Index Per Article: 14.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2016] [Accepted: 05/08/2017] [Indexed: 12/18/2022] Open
Abstract
Plastids are supported by a wide range of proteins encoded within the nucleus and imported from the cytoplasm. These plastid-targeted proteins may originate from the endosymbiont, the host, or other sources entirely. Here, we identify and characterise 770 plastid-targeted proteins that are conserved across the ochrophytes, a major group of algae including diatoms, pelagophytes and kelps, that possess plastids derived from red algae. We show that the ancestral ochrophyte plastid proteome was an evolutionary chimera, with 25% of its phylogenetically tractable nucleus-encoded proteins deriving from green algae. We additionally show that functional mixing of host and plastid proteomes, such as through dual-targeting, is an ancestral feature of plastid evolution. Finally, we detect a clear phylogenetic signal from one ochrophyte subgroup, the lineage containing pelagophytes and dictyochophytes, in plastid-targeted proteins from another major algal lineage, the haptophytes. This may represent a possible serial endosymbiosis event deep in eukaryotic evolutionary history. DOI:http://dx.doi.org/10.7554/eLife.23717.001 The cells of most plants and algae contain compartments called chloroplasts that enable them to capture energy from sunlight in a process known as photosynthesis. Chloroplasts are the remnants of photosynthetic bacteria that used to live freely in the environment until they were consumed by a larger cell. “Complex” chloroplasts can form if a cell that already has a chloroplast is swallowed by another cell. The most abundant algae in the oceans are known as diatoms. These algae belong to a group called the stramenopiles, which also includes giant seaweeds such as kelp. The stramenopiles have a complex chloroplast that they acquired from a red alga (a relative of the seaweed used in sushi). However, some of the proteins in their chloroplasts are from other sources, such as the green algal relatives of plants, and it was not clear how these chloroplast proteins have contributed to the evolution of this group. Many of the proteins that chloroplasts need to work properly are produced by the host cell and are then transported into the chloroplasts. Dorrell et al. studied the genetic material of many stramenopile species and identified 770 chloroplast-targeted proteins that are predicted to underpin the origins of this group. Experiments in a diatom called Phaeodactylum confirmed these predictions and show that many of these chloroplast-targeted proteins have been recruited from green algae, bacteria, and other compartments within the host cell to support the chloroplast. Further experiments suggest that another major group of algae called the haptophytes once had a stramenopile chloroplast. The current haptophyte chloroplast does not come from the stramenopiles so the haptophytes appear to have replaced their chloroplasts at least once in their evolutionary history. The findings show that algal chloroplasts are mosaics, supported by proteins from many different species. This helps us understand why certain species succeed in the wild and how they may respond to environmental changes in the oceans. In the future, these findings may help researchers to engineer new species of algae and plants for food and fuel production. DOI:http://dx.doi.org/10.7554/eLife.23717.002
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Affiliation(s)
- Richard G Dorrell
- IBENS, Département de Biologie, École Normale Supérieure, CNRS, Inserm, PSL Research University, Paris, France
| | - Gillian Gile
- School of Life Sciences, Arizona State University, Tempe, United States
| | - Giselle McCallum
- IBENS, Département de Biologie, École Normale Supérieure, CNRS, Inserm, PSL Research University, Paris, France
| | - Raphaël Méheust
- Institut de Biologie Paris-Seine, Université Pierre et Marie Curie, Paris, France
| | - Eric P Bapteste
- Institut de Biologie Paris-Seine, Université Pierre et Marie Curie, Paris, France
| | | | | | | | - Daniel J Richter
- Sorbonne Universités, Université Pierre et Marie Curie, CNRS UMR 7144.,Adaptation et Diversité en Milieu Marin, Équipe EPEP, Station Biologique de Roscoff, Roscoff, France
| | - Chris Bowler
- IBENS, Département de Biologie, École Normale Supérieure, CNRS, Inserm, PSL Research University, Paris, France
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Evolution of the Tetrapyrrole Biosynthetic Pathway in Secondary Algae: Conservation, Redundancy and Replacement. PLoS One 2016; 11:e0166338. [PMID: 27861576 PMCID: PMC5115734 DOI: 10.1371/journal.pone.0166338] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2016] [Accepted: 10/26/2016] [Indexed: 11/29/2022] Open
Abstract
Tetrapyrroles such as chlorophyll and heme are indispensable for life because they are involved in energy fixation and consumption, i.e. photosynthesis and oxidative phosphorylation. In eukaryotes, the tetrapyrrole biosynthetic pathway is shaped by past endosymbioses. We investigated the origins and predicted locations of the enzymes of the heme pathway in the chlorarachniophyte Bigelowiella natans, the cryptophyte Guillardia theta, the “green” dinoflagellate Lepidodinium chlorophorum, and three dinoflagellates with diatom endosymbionts (“dinotoms”): Durinskia baltica, Glenodinium foliaceum and Kryptoperidinium foliaceum. Bigelowiella natans appears to contain two separate heme pathways analogous to those found in Euglena gracilis; one is predicted to be mitochondrial-cytosolic, while the second is predicted to be plastid-located. In the remaining algae, only plastid-type tetrapyrrole synthesis is present, with a single remnant of the mitochondrial-cytosolic pathway, a ferrochelatase of G. theta putatively located in the mitochondrion. The green dinoflagellate contains a single pathway composed of mostly rhodophyte-origin enzymes, and the dinotoms hold two heme pathways of apparently plastidal origin. We suggest that heme pathway enzymes in B. natans and L. chlorophorum share a predominantly rhodophytic origin. This implies the ancient presence of a rhodophyte-derived plastid in the chlorarachniophyte alga, analogous to the green dinoflagellate, or an exceptionally massive horizontal gene transfer.
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Nishimura Y, Tanifuji G, Kamikawa R, Yabuki A, Hashimoto T, Inagaki Y. Mitochondrial Genome of Palpitomonas bilix: Derived Genome Structure and Ancestral System for Cytochrome c Maturation. Genome Biol Evol 2016; 8:3090-3098. [PMID: 27604877 PMCID: PMC5174734 DOI: 10.1093/gbe/evw217] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
We here reported the mitochondrial (mt) genome of one of the heterotrophic microeukaryotes related to cryptophytes, Palpitomonas bilix. The P. bilix mt genome was found to be a linear molecule composed of “single copy region” (∼16 kb) and repeat regions (∼30 kb) arranged in an inverse manner at both ends of the genome. Linear mt genomes with large inverted repeats are known for three distantly related eukaryotes (including P. bilix), suggesting that this particular mt genome structure has emerged at least three times in the eukaryotic tree of life. The P. bilix mt genome contains 47 protein-coding genes including ccmA, ccmB, ccmC, and ccmF, which encode protein subunits involved in the system for cytochrome c maturation inherited from a bacterium (System I). We present data indicating that the phylogenetic relatives of P. bilix, namely, cryptophytes, goniomonads, and kathablepharids, utilize an alternative system for cytochrome c maturation, which has most likely emerged during the evolution of eukaryotes (System III). To explain the distribution of Systems I and III in P. bilix and its phylogenetic relatives, two scenarios are possible: (i) System I was replaced by System III on the branch leading to the common ancestor of cryptophytes, goniomonads, and kathablepharids, and (ii) the two systems co-existed in their common ancestor, and lost differentially among the four descendants.
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Affiliation(s)
- Yuki Nishimura
- Graduate School of Life and Environmental Sciences, University of Tsukuba, Tsukuba, Japan Present address: Japan Collection of Microorganisms/Microbe Division, RIKEN BioResource Center, Japan Collection of Microorganisms Microbe Division, Tsukuba, Japan
| | - Goro Tanifuji
- Graduate School of Life and Environmental Sciences, University of Tsukuba, Tsukuba, Japan Present address: Department of Zoology, National Museum of Nature and Science, Tsukuba, Japan
| | - Ryoma Kamikawa
- Graduate School of Global Environmental Studies and Graduate School of Human and Environmental Studies, Kyoto University, Kyoto, Japan
| | - Akinori Yabuki
- Japan Agency for Marine-Earth Science and Technology (JAMSTEC), Yokosuka, Japan
| | - Tetsuo Hashimoto
- Graduate School of Life and Environmental Sciences, University of Tsukuba, Tsukuba, Japan Center for Computational Sciences, University of Tsukuba, Tsukuba, Japan
| | - Yuji Inagaki
- Graduate School of Life and Environmental Sciences, University of Tsukuba, Tsukuba, Japan Center for Computational Sciences, University of Tsukuba, Tsukuba, Japan
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Kim E, Sprung B, Duhamel S, Filardi C, Kyoon Shin M. Oligotrophic lagoons of the South Pacific Ocean are home to a surprising number of novel eukaryotic microorganisms. Environ Microbiol 2016; 18:4549-4563. [PMID: 27581800 DOI: 10.1111/1462-2920.13523] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2016] [Accepted: 08/30/2016] [Indexed: 12/20/2022]
Abstract
The diversity of microbial eukaryotes was surveyed by environmental sequencing from tropical lagoon sites of the South Pacific, collected through the American Museum of Natural History (AMNH)'s Explore21 expedition to the Solomon Islands in September 2013. The sampled lagoons presented low nutrient concentrations typical of oligotrophic waters, but contained levels of chlorophyll a, a proxy for phytoplankton biomass, characteristic of meso- to eutrophic waters. Two 18S rDNA hypervariable sites, the V4 and V8-V9 regions, were amplified from the total of eight lagoon samples and sequenced on the MiSeq system. After assembly, clustering at 97% similarity, and removal of singletons and chimeras, a total of 2741 (V4) and 2606 (V8-V9) operational taxonomic units (OTUs) were identified. Taxonomic annotation of these reads, including phylogeny, was based on a combination of automated pipeline and manual inspection. About 18.4% (V4) and 13.8% (V8-V9) of the OTUs could not be assigned to any of the known eukaryotic groups. Of these, we focused on OTUs that were not divergent and possessed multiple sources of evidence for their existence. Phylogenetic analyses of these sequences revealed more than ten branches that might represent new deeply-branching lineages of microbial eukaryotes, currently without any cultured representatives or morphological information.
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Affiliation(s)
- Eunsoo Kim
- Division of Invertebrate Zoology and Sackler Institute for Comparative Genomics, American Museum of Natural History, New York, NY, 10024, USA
| | - Ben Sprung
- Department of Biology, University of Pennsylvania, Philadelphia, PA, 19104, USA
| | - Solange Duhamel
- Lamont-Doherty Earth Observatory, Division of Biology and Paleo Environment, Columbia University, Palisades, NY, 10964, USA
| | - Christopher Filardi
- Center for Biodiversity and Conservation, American Museum of Natural History, New York, NY, 10024, USA
| | - Mann Kyoon Shin
- Department of Biological Sciences, University of Ulsan, Nam-Gu, Ulsan, 44610, South Korea
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Wang HC, Susko E, Roger AJ. Split-specific bootstrap measures for quantifying phylogenetic stability and the influence of taxon selection. Mol Phylogenet Evol 2016; 105:114-125. [PMID: 27568211 DOI: 10.1016/j.ympev.2016.08.017] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2015] [Revised: 08/12/2016] [Accepted: 08/23/2016] [Indexed: 11/16/2022]
Abstract
Assessing the robustness of an inferred phylogeny is an important element of phylogenetics. This is typically done with measures of stabilities at the internal branches and the variation of the positions of the leaf nodes. The bootstrap support for branches in maximum parsimony, distance and maximum likelihood estimation, or posterior probabilities in Bayesian inference, measure the uncertainty about a branch due to the sampling of the sites from genes or sampling genes from genomes. However, these measures do not reveal how taxon sampling affects branch support and the effects of taxon sampling on the estimated phylogeny. An internal branch in a phylogenetic tree can be viewed as a split that separates the taxa into two nonempty complementary subsets. We develop several split-specific measures of stability determined from bootstrap support for quartets. These include BPtaxon_split (average bootstrap percentage [BP] for all quartets involving a taxon within a split), BPsplit (BPtaxon_split averaged over taxa), BPtaxon (BPtaxon_split averaged over splits) and RBIC-taxon (average BP over all splits after removing a taxon). We also develop a pruned-tree distance metric. Application of our measures to empirical and simulated data illustrate that existing measures of overall stability can fail to detect taxa that are the primary source of a split-specific instability. Moreover, we show that the use of many reduced sets of quartets is important in being able to detect the influence of joint sets of taxa rather than individual taxa. These new measures are valuable diagnostic tools to guide taxon sampling in phylogenetic experimental design.
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Affiliation(s)
- Huai-Chun Wang
- Department of Mathematics and Statistics, Dalhousie University, Halifax, Nova Scotia B3H 4R2, Canada; Department of Biochemistry and Molecular Biology, Dalhousie University, Halifax, Nova Scotia B3H 4R2, Canada; Centre for Comparative Genomics and Evolutionary Bioinformatics, Dalhousie University, Canada.
| | - Edward Susko
- Department of Mathematics and Statistics, Dalhousie University, Halifax, Nova Scotia B3H 4R2, Canada; Centre for Comparative Genomics and Evolutionary Bioinformatics, Dalhousie University, Canada
| | - Andrew J Roger
- Department of Biochemistry and Molecular Biology, Dalhousie University, Halifax, Nova Scotia B3H 4R2, Canada; Centre for Comparative Genomics and Evolutionary Bioinformatics, Dalhousie University, Canada; Canadian Institute for Advanced Research, Program in Integrated Microbial Biodiversity, Canada
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He D, Sierra R, Pawlowski J, Baldauf SL. Reducing long-branch effects in multi-protein data uncovers a close relationship between Alveolata and Rhizaria. Mol Phylogenet Evol 2016; 101:1-7. [DOI: 10.1016/j.ympev.2016.04.033] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2014] [Revised: 03/23/2016] [Accepted: 04/26/2016] [Indexed: 12/22/2022]
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Del Campo J, Guillou L, Hehenberger E, Logares R, López-García P, Massana R. Ecological and evolutionary significance of novel protist lineages. Eur J Protistol 2016; 55:4-11. [PMID: 26996654 DOI: 10.1016/j.ejop.2016.02.002] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2015] [Revised: 01/23/2016] [Accepted: 02/12/2016] [Indexed: 01/12/2023]
Abstract
Environmental molecular surveys targeting protist diversity have unveiled novel and uncultured lineages in a variety of ecosystems, ranging from completely new high-rank lineages, to new taxa moderately related to previously described organisms. The ecological roles of some of these novel taxa have been studied, showing that in certain habitats they may be responsible for critical environmental processes. Moreover, from an evolutionary perspective they still need to be included in a more accurate and wider understanding of the eukaryotic tree of life. These seminal discoveries promoted the development and use of a wide range of more in-depth culture-independent approaches to access this diversity, from metabarcoding and metagenomics to single cell genomics and FISH. Nonetheless, culturing using classical or innovative approaches is also essential to better characterize this new diversity. Ecologists and evolutionary biologists now face the challenge of apprehending the significance of this new diversity within the eukaryotic tree of life.
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Affiliation(s)
- Javier Del Campo
- Department of Botany, University of British Columbia, Vancouver, Canada; Department of Marine Biology and Oceanography, Institut de Ciències del Mar (CSIC), Barcelona, Catalonia, Spain.
| | - Laure Guillou
- Sorbonne Universités, UPMC Univ. Paris 6, CNRS, Adaptation et Diversité en Milieu Marin (UMR 7144), équipe DIPO, Station Biologique de Roscoff, 29688 Roscoff, France
| | | | - Ramiro Logares
- Department of Marine Biology and Oceanography, Institut de Ciències del Mar (CSIC), Barcelona, Catalonia, Spain
| | - Purificación López-García
- Ecologie Systématique Evolution, CNRS, Université Paris-Sud, AgroParisTech, Université Paris-Saclay, 91400 Orsay, France
| | - Ramon Massana
- Department of Marine Biology and Oceanography, Institut de Ciències del Mar (CSIC), Barcelona, Catalonia, Spain
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Burki F, Kaplan M, Tikhonenkov DV, Zlatogursky V, Minh BQ, Radaykina LV, Smirnov A, Mylnikov AP, Keeling PJ. Untangling the early diversification of eukaryotes: a phylogenomic study of the evolutionary origins of Centrohelida, Haptophyta and Cryptista. Proc Biol Sci 2016; 283:rspb.2015.2802. [PMID: 26817772 DOI: 10.1098/rspb.2015.2802] [Citation(s) in RCA: 194] [Impact Index Per Article: 24.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2015] [Accepted: 12/22/2015] [Indexed: 12/16/2022] Open
Abstract
Assembling the global eukaryotic tree of life has long been a major effort of Biology. In recent years, pushed by the new availability of genome-scale data for microbial eukaryotes, it has become possible to revisit many evolutionary enigmas. However, some of the most ancient nodes, which are essential for inferring a stable tree, have remained highly controversial. Among other reasons, the lack of adequate genomic datasets for key taxa has prevented the robust reconstruction of early diversification events. In this context, the centrohelid heliozoans are particularly relevant for reconstructing the tree of eukaryotes because they represent one of the last substantial groups that was missing large and diverse genomic data. Here, we filled this gap by sequencing high-quality transcriptomes for four centrohelid lineages, each corresponding to a different family. Combining these new data with a broad eukaryotic sampling, we produced a gene-rich taxon-rich phylogenomic dataset that enabled us to refine the structure of the tree. Specifically, we show that (i) centrohelids relate to haptophytes, confirming Haptista; (ii) Haptista relates to SAR; (iii) Cryptista share strong affinity with Archaeplastida; and (iv) Haptista + SAR is sister to Cryptista + Archaeplastida. The implications of this topology are discussed in the broader context of plastid evolution.
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Affiliation(s)
- Fabien Burki
- Department of Botany, University of British Columbia, Vancouver, British Columbia, Canada
| | - Maia Kaplan
- Department of Botany, University of British Columbia, Vancouver, British Columbia, Canada
| | - Denis V Tikhonenkov
- Department of Botany, University of British Columbia, Vancouver, British Columbia, Canada Institute for Biology of Inland Waters, Russian Academy of Sciences, Borok, Russia
| | - Vasily Zlatogursky
- Department of Invertebrate Zoology, St Petersburg State University, St Petersburg, Russia
| | - Bui Quang Minh
- Center for Integrative Bioinformatics, Max F. Perutz Laboratories, University of Vienna, Medical University of Vienna, Vienna, Austria
| | - Liudmila V Radaykina
- Institute for Biology of Inland Waters, Russian Academy of Sciences, Borok, Russia
| | - Alexey Smirnov
- Department of Invertebrate Zoology, St Petersburg State University, St Petersburg, Russia
| | - Alexander P Mylnikov
- Institute for Biology of Inland Waters, Russian Academy of Sciences, Borok, Russia
| | - Patrick J Keeling
- Department of Botany, University of British Columbia, Vancouver, British Columbia, Canada Canadian Institute for Advanced Research, Integrated Microbial Biodiversity Program, Toronto, Ontario, Canada
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Cavalier-Smith T, Chao EE, Lewis R. Multiple origins of Heliozoa from flagellate ancestors: New cryptist subphylum Corbihelia, superclass Corbistoma, and monophyly of Haptista, Cryptista, Hacrobia and Chromista. Mol Phylogenet Evol 2015; 93:331-62. [DOI: 10.1016/j.ympev.2015.07.004] [Citation(s) in RCA: 63] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2015] [Revised: 06/25/2015] [Accepted: 07/10/2015] [Indexed: 11/30/2022]
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Yamagishi T, Kurihara A, Kawai H. A Ribbon-like Structure in the Ejective Organelle of the Green Microalga Pyramimonas parkeae (Prasinophyceae) Consists of Core Histones and Polymers Containing N-acetyl-glucosamine. Protist 2015; 166:522-33. [DOI: 10.1016/j.protis.2015.08.003] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2015] [Revised: 07/17/2015] [Accepted: 08/20/2015] [Indexed: 11/24/2022]
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36
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Gawryluk RM, Eme L, Roger AJ. Gene fusion, fission, lateral transfer, and loss: Not-so-rare events in the evolution of eukaryotic ATP citrate lyase. Mol Phylogenet Evol 2015; 91:12-6. [DOI: 10.1016/j.ympev.2015.05.010] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2014] [Revised: 05/07/2015] [Accepted: 05/11/2015] [Indexed: 10/23/2022]
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Speijer D, Lukeš J, Eliáš M. Sex is a ubiquitous, ancient, and inherent attribute of eukaryotic life. Proc Natl Acad Sci U S A 2015; 112:8827-34. [PMID: 26195746 PMCID: PMC4517231 DOI: 10.1073/pnas.1501725112] [Citation(s) in RCA: 171] [Impact Index Per Article: 19.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
Sexual reproduction and clonality in eukaryotes are mostly seen as exclusive, the latter being rather exceptional. This view might be biased by focusing almost exclusively on metazoans. We analyze and discuss reproduction in the context of extant eukaryotic diversity, paying special attention to protists. We present results of phylogenetically extended searches for homologs of two proteins functioning in cell and nuclear fusion, respectively (HAP2 and GEX1), providing indirect evidence for these processes in several eukaryotic lineages where sex has not been observed yet. We argue that (i) the debate on the relative significance of sex and clonality in eukaryotes is confounded by not appropriately distinguishing multicellular and unicellular organisms; (ii) eukaryotic sex is extremely widespread and already present in the last eukaryotic common ancestor; and (iii) the general mode of existence of eukaryotes is best described by clonally propagating cell lines with episodic sex triggered by external or internal clues. However, important questions concern the relative longevity of true clonal species (i.e., species not able to return to sexual procreation anymore). Long-lived clonal species seem strikingly rare. We analyze their properties in the light of meiotic sex development from existing prokaryotic repair mechanisms. Based on these considerations, we speculate that eukaryotic sex likely developed as a cellular survival strategy, possibly in the context of internal reactive oxygen species stress generated by a (proto) mitochondrion. Thus, in the context of the symbiogenic model of eukaryotic origin, sex might directly result from the very evolutionary mode by which eukaryotic cells arose.
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Affiliation(s)
- Dave Speijer
- Department of Medical Biochemistry, Academic Medical Center, University of Amsterdam, 1105 AZ, Amsterdam, The Netherlands;
| | - Julius Lukeš
- Institute of Parasitology, Biology Centre, Czech Academy of Sciences, and Faculty of Sciences, University of South Bohemia, 370 05 České Budějovice, Czech Republic; Canadian Institute for Advanced Research, Toronto, ON, Canada M5G 1Z8
| | - Marek Eliáš
- Department of Biology and Ecology, University of Ostrava, 710 00 Ostrava, Czech Republic
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Ševčíková T, Horák A, Klimeš V, Zbránková V, Demir-Hilton E, Sudek S, Jenkins J, Schmutz J, Přibyl P, Fousek J, Vlček Č, Lang BF, Oborník M, Worden AZ, Eliáš M. Updating algal evolutionary relationships through plastid genome sequencing: did alveolate plastids emerge through endosymbiosis of an ochrophyte? Sci Rep 2015; 5:10134. [PMID: 26017773 PMCID: PMC4603697 DOI: 10.1038/srep10134] [Citation(s) in RCA: 66] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2015] [Accepted: 03/31/2015] [Indexed: 01/15/2023] Open
Abstract
Algae with secondary plastids of a red algal origin, such as ochrophytes (photosynthetic stramenopiles), are diverse and ecologically important, yet their evolutionary history remains controversial. We sequenced plastid genomes of two ochrophytes, Ochromonas sp. CCMP1393 (Chrysophyceae) and Trachydiscus minutus (Eustigmatophyceae). A shared split of the clpC gene as well as phylogenomic analyses of concatenated protein sequences demonstrated that chrysophytes and eustigmatophytes form a clade, the Limnista, exhibiting an unexpectedly elevated rate of plastid gene evolution. Our analyses also indicate that the root of the ochrophyte phylogeny falls between the recently redefined Khakista and Phaeista assemblages. Taking advantage of the expanded sampling of plastid genome sequences, we revisited the phylogenetic position of the plastid of Vitrella brassicaformis, a member of Alveolata with the least derived plastid genome known for the whole group. The results varied depending on the dataset and phylogenetic method employed, but suggested that the Vitrella plastids emerged from a deep ochrophyte lineage rather than being derived vertically from a hypothetical plastid-bearing common ancestor of alveolates and stramenopiles. Thus, we hypothesize that the plastid in Vitrella, and potentially in other alveolates, may have been acquired by an endosymbiosis of an early ochrophyte.
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Affiliation(s)
- Tereza Ševčíková
- University of Ostrava, Faculty of Science, Department of Biology and Ecology, Life Science Research Centre, Chittussiho 10, 710 00 Ostrava, Czech Republic
| | - Aleš Horák
- Institute of Parasitology, Biology Centre, Czech Academy of Sciences, Branišovská 31, 370 05 České Budějovice, Czech Republic.,University of South Bohemia, Faculty of Science, Branišovská 1760, 370 05 České Budějovice, Czech Republic
| | - Vladimír Klimeš
- University of Ostrava, Faculty of Science, Department of Biology and Ecology, Life Science Research Centre, Chittussiho 10, 710 00 Ostrava, Czech Republic
| | - Veronika Zbránková
- University of Ostrava, Faculty of Science, Department of Biology and Ecology, Life Science Research Centre, Chittussiho 10, 710 00 Ostrava, Czech Republic
| | - Elif Demir-Hilton
- Monterey Bay Aquarium Research Institute (MBARI), Moss Landing, CA 95039, USA
| | - Sebastian Sudek
- Monterey Bay Aquarium Research Institute (MBARI), Moss Landing, CA 95039, USA
| | - Jerry Jenkins
- US Department of Energy Joint Genome Institute, Walnut Creek, California 94598, USA
| | - Jeremy Schmutz
- HudsonAlpha Institute for Biotechnology, 601 Genome Way NW, Huntsville, Alabama 35806, USA
| | - Pavel Přibyl
- Centre for Algology and Biorefinery Research Centre of Competence, Institute of Botany, Czech Academy of Sciences, Dukelská 135, 379 82 Třeboň, Czech Republic
| | - Jan Fousek
- Institute of Molecular Genetics, Czech Academy of Sciences, Vídeňská 1083, 142 20 Prague 4, Czech Republic
| | - Čestmír Vlček
- Institute of Molecular Genetics, Czech Academy of Sciences, Vídeňská 1083, 142 20 Prague 4, Czech Republic
| | - B Franz Lang
- Département de Biochimie, Centre Robert-Cedergren, Université de Montréal, 2900 Boulevard Edouard Montpetit, Montréal, Québec, H3C 3J7, Canada
| | - Miroslav Oborník
- Institute of Parasitology, Biology Centre, Czech Academy of Sciences, Branišovská 31, 370 05 České Budějovice, Czech Republic.,University of South Bohemia, Faculty of Science, Branišovská 1760, 370 05 České Budějovice, Czech Republic
| | - Alexandra Z Worden
- Monterey Bay Aquarium Research Institute (MBARI), Moss Landing, CA 95039, USA.,Integrated Microbial Biodiversity Program, Canadian Institute for Advanced Research, Toronto, M5G 1Z8, Canada
| | - Marek Eliáš
- University of Ostrava, Faculty of Science, Department of Biology and Ecology, Life Science Research Centre, Chittussiho 10, 710 00 Ostrava, Czech Republic
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Wheeler G, Ishikawa T, Pornsaksit V, Smirnoff N. Evolution of alternative biosynthetic pathways for vitamin C following plastid acquisition in photosynthetic eukaryotes. eLife 2015; 4. [PMID: 25768426 PMCID: PMC4396506 DOI: 10.7554/elife.06369] [Citation(s) in RCA: 96] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2015] [Accepted: 03/12/2015] [Indexed: 01/08/2023] Open
Abstract
Ascorbic acid (vitamin C) is an enzyme co-factor in eukaryotes that also plays a critical role in protecting photosynthetic eukaryotes against damaging reactive oxygen species derived from the chloroplast. Many animal lineages, including primates, have become ascorbate auxotrophs due to the loss of the terminal enzyme in their biosynthetic pathway, l-gulonolactone oxidase (GULO). The alternative pathways found in land plants and Euglena use a different terminal enzyme, l-galactonolactone dehydrogenase (GLDH). The evolutionary processes leading to these differing pathways and their contribution to the cellular roles of ascorbate remain unclear. Here we present molecular and biochemical evidence demonstrating that GULO was functionally replaced with GLDH in photosynthetic eukaryote lineages following plastid acquisition. GULO has therefore been lost repeatedly throughout eukaryote evolution. The formation of the alternative biosynthetic pathways in photosynthetic eukaryotes uncoupled ascorbate synthesis from hydrogen peroxide production and likely contributed to the rise of ascorbate as a major photoprotective antioxidant. DOI:http://dx.doi.org/10.7554/eLife.06369.001 Animals, plants, algae and other eukaryotic organisms all need vitamin C to enable many of their enzymes to work properly. Vitamin C also protects plant and algal cells from damage by molecules called reactive oxygen species (ROS), which can be produced when these cells harvest energy from sunlight in a process called photosynthesis. Photosynthesis occurs inside structures called chloroplasts, and has evolved on multiple occasions in eukaryotes when non-photosynthetic organisms acquired chloroplasts from other algae and then had to develop improved defences against ROS. There are several steps involved in the production of vitamin C. In many animals, an enzyme called GULO carries out the final step by converting a molecule known as an aldonolactone into vitamin C; this reaction also produces ROS as a waste product. The GULO enzyme is missing in humans, primates and some other groups of animals, so these organisms must get all the vitamin C they need from their diet. Plants and algae use a different enzyme—called GLDH—to make vitamin C from aldonolactone. GLDH is very similar to GULO, but it does not produce ROS as a waste product. It is not clear how the different pathways have evolved, or why some animals have lost the ability to make their own vitamin C. Here, Wheeler et al. used genetics and biochemistry to investigate the evolutionary origins of vitamin C production in a variety of eukaryotic organisms. This investigation revealed that although GULO is missing from the insects and several other groups of animals, it is present in the sponges and many other eukaryotes. This suggests that GULO evolved in early eukaryotic organisms and has since been lost by the different groups of animals. On the other hand, GLDH is only found in plants and the other eukaryotes that can photosynthesize. Wheeler et al.'s findings suggest that GULO has been lost and replaced by GLDH in all plants and algae following their acquisition of chloroplasts. GDLH allows plants and algae to make vitamin C without also producing ROS, which could explain why vitamin C has been able to take on an extra role in these organisms. The results allow us to better understand the functions of vitamin C in photosynthetic organisms and the processes associated with the acquisition of chloroplasts during evolution. DOI:http://dx.doi.org/10.7554/eLife.06369.002
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Affiliation(s)
- Glen Wheeler
- Marine Biological Association, Plymouth, United Kingdom
| | - Takahiro Ishikawa
- Department of Life Science and Biotechnology, Shimane University, Matsue, Japan
| | - Varissa Pornsaksit
- Biosciences, College of Life and Environmental Sciences, University of Exeter, Exeter, United Kingdom
| | - Nicholas Smirnoff
- Biosciences, College of Life and Environmental Sciences, University of Exeter, Exeter, United Kingdom
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Abstract
The large phylogenetic distance separating eukaryotic genes and their archaeal orthologs has prevented identification of the position of the eukaryotic root in phylogenomic studies. Recently, an innovative approach has been proposed to circumvent this issue: the use as phylogenetic markers of proteins that have been transferred from bacterial donor sources to eukaryotes, after their emergence from Archaea. Using this approach, two recent independent studies have built phylogenomic datasets based on bacterial sequences, leading to different predictions of the eukaryotic root. Taking advantage of additional genome sequences from the jakobid Andalucia godoyi and the two known malawimonad species (Malawimonas jakobiformis and Malawimonas californiana), we reanalyzed these two phylogenomic datasets. We show that both datasets pinpoint the same phylogenetic position of the eukaryotic root that is between "Unikonta" and "Bikonta," with malawimonad and collodictyonid lineages on the Unikonta side of the root. Our results firmly indicate that (i) the supergroup Excavata is not monophyletic and (ii) the last common ancestor of eukaryotes was a biflagellate organism. Based on our results, we propose to rename the two major eukaryotic groups Unikonta and Bikonta as Opimoda and Diphoda, respectively.
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Jackson CJ, Reyes-Prieto A. The mitochondrial genomes of the glaucophytes Gloeochaete wittrockiana and Cyanoptyche gloeocystis: multilocus phylogenetics suggests a monophyletic archaeplastida. Genome Biol Evol 2014; 6:2774-85. [PMID: 25281844 PMCID: PMC4224345 DOI: 10.1093/gbe/evu218] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/29/2014] [Indexed: 12/16/2022] Open
Abstract
A significant limitation when testing the putative single origin of primary plastids and the monophyly of the Archaeplastida supergroup, comprised of the red algae, viridiplants, and glaucophytes, is the scarce nuclear and organellar genome data available from the latter lineage. The Glaucophyta are a key algal group when investigating the origin and early diversification of photosynthetic eukaryotes. However, so far only the plastid and mitochondrial genomes of the glaucophytes Cyanophora paradoxa (strain CCMP 329) and Glaucocystis nostochinearum (strain UTEX 64) have been completely sequenced. Here, we present the complete mitochondrial genomes of Gloeochaete wittrockiana SAG 46.84 (36.05 kb; 33 protein-coding genes, 6 unidentified open reading frames [ORFs], and 28 transfer RNAs [tRNAs]) and Cyanoptyche gloeocystis SAG 4.97 (33.24 kb; 33 protein-coding genes, 6 unidentified ORFs, and 26 tRNAs), which represent two genera distantly related to the "well-known" Cyanophora and Glaucocystis. The mitochondrial gene repertoire of the four glaucophyte species is highly conserved, whereas the gene order shows considerable variation. Phylogenetic analyses of 14 mitochondrial genes from representative taxa from the major eukaryotic supergroups, here including novel sequences from the glaucophytes Cyanophora tetracyanea (strain NIES-764) and Cyanophora biloba (strain UTEX LB 2766), recover a clade uniting the three Archaeplastida lineages; this recovery is dependent on our novel glaucophyte data, demonstrating the importance of greater taxon sampling within the glaucophytes.
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Affiliation(s)
- Christopher J Jackson
- Department of Biology, University of New Brunswick, Fredericton, New Brunswick, Canada
| | - Adrian Reyes-Prieto
- Department of Biology, University of New Brunswick, Fredericton, New Brunswick, Canada Department of Biology, University of New Brunswick, Fredericton, New Brunswick, Canada
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