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Shiratori T, Ishida KI. Rhabdamoeba marina is a heterotrophic relative of chlorarachnid algae. J Eukaryot Microbiol 2024; 71:e13010. [PMID: 37941507 DOI: 10.1111/jeu.13010] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2023] [Accepted: 10/27/2023] [Indexed: 11/10/2023]
Abstract
Rhabdamoeba marina is a unique and poorly reported amoeba with an uncertain phylogenetic position. We successfully cultured R. marina from coastal seawater in Japan and performed a molecular phylogenetic analysis using the small subunit ribosomal RNA (SSU rRNA) gene sequence. Our phylogenetic analysis showed that R. marina branched as a basal lineage of Chlorarachnea, a group of marine photosynthetic algae belonging to the phylum Cercozoa within the supergroup Rhizaria. By comparing the ecological and morphological characteristics of R. marina with those of photosynthetic chlorarachneans and other cercozoans, we gained insight into the evolution and acquisition of plastids in Chlorarachnida.
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Affiliation(s)
- Takashi Shiratori
- Institute of Life and Environmental Sciences, University of Tsukuba, Tsukuba, Japan
| | - Ken-Ichiro Ishida
- Institute of Life and Environmental Sciences, University of Tsukuba, Tsukuba, Japan
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2
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Geiger O, Sanchez-Flores A, Padilla-Gomez J, Degli Esposti M. Multiple approaches of cellular metabolism define the bacterial ancestry of mitochondria. SCIENCE ADVANCES 2023; 9:eadh0066. [PMID: 37556552 PMCID: PMC10411912 DOI: 10.1126/sciadv.adh0066] [Citation(s) in RCA: 9] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/07/2023] [Accepted: 05/11/2023] [Indexed: 08/11/2023]
Abstract
We breathe at the molecular level when mitochondria in our cells consume oxygen to extract energy from nutrients. Mitochondria are characteristic cellular organelles that derive from aerobic bacteria and carry out oxidative phosphorylation and other key metabolic pathways in eukaryotic cells. The precise bacterial origin of mitochondria and, consequently, the ancestry of the aerobic metabolism of our cells remain controversial despite the vast genomic information that is now available. Here, we use multiple approaches to define the most likely living relatives of the ancestral bacteria from which mitochondria originated. These bacteria live in marine environments and exhibit the highest frequency of aerobic traits and genes for the metabolism of fundamental lipids that are present in the membranes of eukaryotes, sphingolipids, and cardiolipin.
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Affiliation(s)
- Otto Geiger
- Center for Genomic Sciences, UNAM Campus de Morelos, Cuernavaca, México
| | - Alejandro Sanchez-Flores
- Unidad Universitaria de Secuenciación Masiva y Bioinformatica, Institute of Biotechnology, UNAM, Cuernavaca, México
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3
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Cavalier-Smith T. Ciliary transition zone evolution and the root of the eukaryote tree: implications for opisthokont origin and classification of kingdoms Protozoa, Plantae, and Fungi. PROTOPLASMA 2022; 259:487-593. [PMID: 34940909 PMCID: PMC9010356 DOI: 10.1007/s00709-021-01665-7] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/21/2020] [Accepted: 05/03/2021] [Indexed: 05/19/2023]
Abstract
I thoroughly discuss ciliary transition zone (TZ) evolution, highlighting many overlooked evolutionarily significant ultrastructural details. I establish fundamental principles of TZ ultrastructure and evolution throughout eukaryotes, inferring unrecognised ancestral TZ patterns for Fungi, opisthokonts, and Corticata (i.e., kingdoms Plantae and Chromista). Typical TZs have a dense transitional plate (TP), with a previously overlooked complex lattice as skeleton. I show most eukaryotes have centriole/TZ junction acorn-V filaments (whose ancestral function was arguably supporting central pair microtubule-nucleating sites; I discuss their role in centriole growth). Uniquely simple malawimonad TZs (without TP, simpler acorn) pinpoint the eukaryote tree's root between them and TP-bearers, highlighting novel superclades. I integrate TZ/ciliary evolution with the best multiprotein trees, naming newly recognised major eukaryote clades and revise megaclassification of basal kingdom Protozoa. Recent discovery of non-photosynthetic phagotrophic flagellates with genome-free plastids (Rhodelphis), the sister group to phylum Rhodophyta (red algae), illuminates plant and chromist early evolution. I show previously overlooked marked similarities in cell ultrastructure between Rhodelphis and Picomonas, formerly considered an early diverging chromist. In both a nonagonal tube lies between their TP and an annular septum surrounding their 9+2 ciliary axoneme. Mitochondrial dense condensations and mitochondrion-linked smooth endomembrane cytoplasmic partitioning cisternae further support grouping Picomonadea and Rhodelphea as new plant phylum Pararhoda. As Pararhoda/Rhodophyta form a robust clade on site-heterogeneous multiprotein trees, I group Pararhoda and Rhodophyta as new infrakingdom Rhodaria of Plantae within subkingdom Biliphyta, which also includes Glaucophyta with fundamentally similar TZ, uniquely in eukaryotes. I explain how biliphyte TZs generated viridiplant stellate-structures.
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4
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Yazaki E, Yabuki A, Imaizumi A, Kume K, Hashimoto T, Inagaki Y. The closest lineage of Archaeplastida is revealed by phylogenomics analyses that include Microheliella maris. Open Biol 2022; 12:210376. [PMID: 35414259 PMCID: PMC9006020 DOI: 10.1098/rsob.210376] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023] Open
Abstract
By clarifying the phylogenetic positions of 'orphan' protists (unicellular micro-eukaryotes with no affinity to extant lineages), we may uncover the novel affiliation between two (or more) major lineages in eukaryotes. Microheliella maris was an orphan protist, which failed to be placed within the previously described lineages by pioneering phylogenetic analyses. In this study, we analysed a 319-gene alignment and demonstrated that M. maris represents a basal lineage of one of the major eukaryotic lineages, Cryptista. We here propose a new clade name 'Pancryptista' for Cryptista plus M. maris. The 319-gene analyses also indicated that M. maris is a key taxon to recover the monophyly of Archaeplastida and the sister relationship between Archaeplastida and Pancryptista, which is collectively called 'CAM clade' here. Significantly, Cryptophyceae tend to be attracted to Rhodophyta depending on the taxon sampling (ex., in the absence of M. maris and Rhodelphidia) and the particular phylogenetic 'signal' most likely hindered the stable recovery of the monophyly of Archaeplastida in previous studies.
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Affiliation(s)
| | - Akinori Yabuki
- Japan Agency for Marine-Earth Science and Technology, Yokosuka, Kanagawa 237-0061, Japan
| | - Ayaka Imaizumi
- College of Biological Sciences, University of Tsukuba, Tsukuba, Ibaraki 305-8572, Japan
| | - Keitaro Kume
- Faculty of Medicine, University of Tsukuba, Tsukuba, Ibaraki 305-8572, Japan
| | - Tetsuo Hashimoto
- Faculty of Life and Environmental Sciences, University of Tsukuba, Tsukuba, Ibaraki 305-8572, Japan,Graduate School of Life and Environmental Sciences, University of Tsukuba, Tsukuba, Ibaraki 305-8572, Japan
| | - Yuji Inagaki
- Graduate School of Life and Environmental Sciences, University of Tsukuba, Tsukuba, Ibaraki 305-8572, Japan,Center for Computational Sciences, University of Tsukuba, Tsukuba, Ibaraki 305-8572, Japan
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5
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Cevallos MA, Degli Esposti M. New Alphaproteobacteria Thrive in the Depths of the Ocean with Oxygen Gradient. Microorganisms 2022; 10:microorganisms10020455. [PMID: 35208909 PMCID: PMC8879329 DOI: 10.3390/microorganisms10020455] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2022] [Revised: 02/10/2022] [Accepted: 02/15/2022] [Indexed: 02/04/2023] Open
Abstract
We survey here the Alphaproteobacteria, a large class encompassing physiologically diverse bacteria which are divided in several orders established since 2007. Currently, there is considerable uncertainty regarding the classification of an increasing number of marine metagenome-assembled genomes (MAGs) that remain poorly defined in their taxonomic position within Alphaproteobacteria. The traditional classification of NCBI taxonomy is increasingly complemented by the Genome Taxonomy Database (GTDB), but the two taxonomies differ considerably in the classification of several Alphaproteobacteria, especially from ocean metagenomes. We analyzed the classification of Alphaproteobacteria lineages that are most common in marine environments, using integrated approaches of phylogenomics and functional profiling of metabolic features that define their aerobic metabolism. Using protein markers such as NuoL, the largest membrane subunit of complex I, we have identified new clades of Alphaproteobacteria that are specific to marine niches with steep oxygen gradients (oxycline). These bacteria have relatives among MAGs found in anoxic strata of Lake Tanganyika and together define a lineage that is distinct from either Rhodospirillales or Sneathiellales. We characterized in particular the new ‘oxycline’ clade. Our analysis of Alphaproteobacteria also reveals new clues regarding the ancestry of mitochondria, which likely evolved in oxycline marine environments.
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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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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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8
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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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9
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Shiratori T, Yabuki A, Ishida KI. Morphology, Ultrastructure, and Phylogeny of Two Novel Species of Ventrifissura (V. oblonga n. sp. and V. velata n. sp., Thecofilosea, Cercozoa). Protist 2020; 171:125731. [PMID: 32464531 DOI: 10.1016/j.protis.2020.125731] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2019] [Revised: 02/05/2020] [Accepted: 04/03/2020] [Indexed: 10/24/2022]
Abstract
Ventrifissura is a group of poorly studied heterotrophic biflagellates in the phylum Cercozoa. Despite a phylogenetic placement with only weak support and a lack of ultrastructural data, Ventrifissura was assigned to Thecofilosea. In the presented study, we established cultures of two novel species of Ventrifissura (V. oblonga n. sp. and V. velata n. sp.) isolated from coastal marine environments in Japan, and performed light and electron microscopy observations and molecular phylogenetic analysis. Transmission electron microscopy revealed that V. oblonga shares several ultrastructural characteristics with thecofilosean flagellates, including permanently condensed chromosomes, a extracellular theca, and slender extrusomes. Molecular phylogenetic analysis could not resolve the phylogenetic position, but the possibility that Ventrifissura clusters into Ventrifilosa was supported by approximately unbiased tests. Based on both morphological and phylogenetic findings, we concluded that Ventrifissura is a basal lineage of Thecofilosea.
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Affiliation(s)
- Takashi Shiratori
- Faculty of Life and Environmental Sciences, University of Tsukuba, Tsukuba, Ibaraki 305-8572, Japan; Japan Agency for Marine-Earth Science and Technology (JAMSTEC), 2-15 Natsushima, Yokosuka, Kanagawa, 237-0061, Japan.
| | - Akinori Yabuki
- Japan Agency for Marine-Earth Science and Technology (JAMSTEC), 2-15 Natsushima, Yokosuka, Kanagawa, 237-0061, Japan
| | - Ken-Ichiro Ishida
- Faculty of Life and Environmental Sciences, University of Tsukuba, Tsukuba, Ibaraki 305-8572, Japan
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10
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Kellogg CTE, McClelland JW, Dunton KH, Crump BC. Strong Seasonality in Arctic Estuarine Microbial Food Webs. Front Microbiol 2019; 10:2628. [PMID: 31849850 PMCID: PMC6896822 DOI: 10.3389/fmicb.2019.02628] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2019] [Accepted: 10/29/2019] [Indexed: 11/17/2022] Open
Abstract
Microbial communities in the coastal Arctic Ocean experience extreme variability in organic matter and inorganic nutrients driven by seasonal shifts in sea ice extent and freshwater inputs. Lagoons border more than half of the Beaufort Sea coast and provide important habitats for migratory fish and seabirds; yet, little is known about the planktonic food webs supporting these higher trophic levels. To investigate seasonal changes in bacterial and protistan planktonic communities, amplicon sequences of 16S and 18S rRNA genes were generated from samples collected during periods of ice-cover (April), ice break-up (June), and open water (August) from shallow lagoons along the eastern Alaska Beaufort Sea coast from 2011 through 2013. Protist communities shifted from heterotrophic to photosynthetic taxa (mainly diatoms) during the winter–spring transition, and then back to a heterotroph-dominated summer community that included dinoflagellates and mixotrophic picophytoplankton such as Micromonas and Bathycoccus. Planktonic parasites belonging to Syndiniales were abundant under ice in winter at a time when allochthonous carbon inputs were low. Bacterial communities shifted from coastal marine taxa (Oceanospirillaceae, Alteromonadales) to estuarine taxa (Polaromonas, Bacteroidetes) during the winter-spring transition, and then to oligotrophic marine taxa (SAR86, SAR92) in summer. Chemolithoautotrophic taxa were abundant under ice, including iron-oxidizing Zetaproteobacteria. These results suggest that wintertime Arctic bacterial communities capitalize on the unique biogeochemical gradients that develop below ice near shore, potentially using chemoautotrophic metabolisms at a time when carbon inputs to the system are low. Co-occurrence networks constructed for each season showed that under-ice networks were dominated by relationships between parasitic protists and other microbial taxa, while spring networks were by far the largest and dominated by bacteria-bacteria co-occurrences. Summer networks were the smallest and least connected, suggesting a more detritus-based food web less reliant on interactions among microbial taxa. Eukaryotic and bacterial community compositions were significantly related to trends in concentrations of stable isotopes of particulate organic carbon and nitrogen, among other physiochemical variables such as dissolved oxygen, salinity, and temperature. This suggests the importance of sea ice cover and terrestrial carbon subsidies in contributing to seasonal trends in microbial communities in the coastal Beaufort Sea.
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Affiliation(s)
| | - James W McClelland
- Marine Science Institute, University of Texas at Austin, Port Aransas, TX, United States
| | - Kenneth H Dunton
- Marine Science Institute, University of Texas at Austin, Port Aransas, TX, United States
| | - Byron C Crump
- College of Earth, Ocean, and Atmospheric Sciences, Oregon State University, Corvallis, OR, United States
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11
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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: 391] [Impact Index Per Article: 78.2] [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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12
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Hofstatter PG, Lahr DJG. All Eukaryotes Are Sexual, unless Proven Otherwise: Many So-Called Asexuals Present Meiotic Machinery and Might Be Able to Have Sex. Bioessays 2019; 41:e1800246. [PMID: 31087693 DOI: 10.1002/bies.201800246] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2018] [Revised: 03/15/2019] [Indexed: 11/07/2022]
Abstract
Here a wide distribution of meiotic machinery is shown, indicating the occurrence of sexual processes in all major eukaryotic groups, without exceptions, including the putative "asexuals." Meiotic machinery has evolved from archaeal DNA repair machinery by means of ancestral gene duplications. Sex is very conserved and widespread in eukaryotes, even though its evolutionary importance is still a matter of debate. The main processes in sex are plasmogamy, followed by karyogamy and meiosis. Meiosis is fundamentally a chromosomal process, which implies recombination and ploidy reduction. Several eukaryotic lineages are proposed to be asexual because their sexual processes are never observed, but presumed asexuality correlates with lack of study. The authors stress the complete lack of meiotic proteins in nucleomorphs and their almost complete loss in the fungus Malassezia. Inversely, complete sets of meiotic proteins are present in fungal groups Glomeromycotina, Trichophyton, and Cryptococcus. Endosymbiont Perkinsela and endoparasitic Microsporidia also present meiotic proteins.
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Affiliation(s)
- Paulo G Hofstatter
- Departamento de ZoologiaRua do Matão, Instituto de Biociências, Universidade de São Paulo, travessa 14, 101CEP., 05508-090, Sâo Paulo, Brazil
| | - Daniel J G Lahr
- Departamento de ZoologiaRua do Matão, Instituto de Biociências, Universidade de São Paulo, travessa 14, 101CEP., 05508-090, Sâo Paulo, Brazil
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13
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Heiss AA, Heiss AW, Lukacs K, Kim E. The flagellar apparatus of the glaucophyte Cyanophora cuspidata. JOURNAL OF PHYCOLOGY 2017; 53:1120-1150. [PMID: 28741699 DOI: 10.1111/jpy.12569] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/24/2017] [Accepted: 06/12/2017] [Indexed: 05/16/2023]
Abstract
Glaucophytes are a kingdom-scale lineage of unicellular algae with uniquely underived plastids. The genus Cyanophora is of particular interest because it is the only glaucophyte that is a flagellate throughout its life cycle, making its morphology more directly comparable than other glaucophytes to other eukaryote flagellates. The ultrastructure of Cyanophora has already been studied, primarily in the 1960s and 1970s. However, the usefulness of that work has been undermined by its own limitations, subsequent misinterpretations, and a recent taxonomic revision of the genus. For example, Cyanophora's microtubular roots have been widely reported as cruciate, with rotationally symmetrical wide and thin roots, although the first ultrastructural work described it as having three wide and one narrow root. We examine Cyanophora cuspidata using scanning and transmission electron microscopy, and construct a model of its cytoskeleton using serial-section TEM. We confirm the earlier model, with asymmetric roots. We describe previously unknown and unsuspected features of its microtubular roots, including (i) a rearrangement of individual microtubules within the posterior right root, (ii) a splitting of the posterior left root into two subroots, and (iii) the convergence and termination of the narrow roots against wider ones in both the anterior and posterior subsystems of the flagellar apparatus. We also describe a large complement of nonmicrotubular components of the cytoskeleton, including a substantial connective between the posterior right root and the anterior basal body. Our work should serve as the starting point for a re-examination of both internal glaucophyte diversity and morphological evolution in eukaryotes.
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Affiliation(s)
- Aaron A Heiss
- Division of Invertebrate Zoology, American Museum of Natural History, Central Park West at 79th St., New York, New York, 10024, USA
- Sackler Institute for Comparative Genomics, American Museum of Natural History, Central Park West at 79th St., New York, New York, 10024, USA
| | - Alaric W Heiss
- Division of Invertebrate Zoology, American Museum of Natural History, Central Park West at 79th St., New York, New York, 10024, USA
| | - Kaleigh Lukacs
- Division of Invertebrate Zoology, American Museum of Natural History, Central Park West at 79th St., New York, New York, 10024, USA
| | - Eunsoo Kim
- Division of Invertebrate Zoology, American Museum of Natural History, Central Park West at 79th St., New York, New York, 10024, USA
- Sackler Institute for Comparative Genomics, American Museum of Natural History, Central Park West at 79th St., New York, New York, 10024, USA
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14
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Shiratori T, Thakur R, Ishida KI. Pseudophyllomitus vesiculosus (Larsen and Patterson 1990) Lee, 2002, a Poorly Studied Phagotrophic Biflagellate is the First Characterized Member of Stramenopile Environmental Clade MAST-6. Protist 2017; 168:439-451. [PMID: 28822908 DOI: 10.1016/j.protis.2017.06.004] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2017] [Revised: 06/20/2017] [Accepted: 06/21/2017] [Indexed: 01/17/2023]
Abstract
There are many eukaryotic lineages that are exclusively composed of environmental sequences and lack information about which species are included. Regarding stramenopiles, at least 18 environmental lineages, known as marine stramenopiles (MAST), have been recognized. Since each MAST lineage forms deep branches in the stramenopiles, the characterization of MAST members is key to understanding the diversity and evolution of stramenopiles. In this study, we established a culture of Pseudophyllomitus vesiculosus, which is a poorly studied phagotrophic flagellate of uncertain taxonomic position. Our molecular phylogenetic analyses based on small subunit ribosomal RNA gene sequences robustly supported the inclusion of P. vesiculosus in the MAST-6 clade. Our microscopic observations indicated that P. vesiculosus shared characteristics with stramenopiles, including an anterior flagellum that exhibits sinusoidal waves and bears tubular mastigonemes. The flagellar apparatus of P. vesiculosus was also similar to that of other stramenopiles in having a transitional helix and five microtubular roots (R1-R4 and S tubules) including R2 that split into two bands. On the other hand, P. vesiculosus was distinguished from other deep-branching stramenopiles by the combination of flagellar apparatus characteristics. Based on the phylogenetic analyses and microscopic observations, we established Pseudophyllomitidae fam. nov in stramenopiles.
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Affiliation(s)
- Takashi Shiratori
- Faculty of Life and Environmental Sciences, University of Tsukuba, Tsukuba, Ibaraki 305-8572, Japan.
| | - Rabindra Thakur
- Graduate School of Life and Environmental Sciences, University of Tsukuba, Tsukuba, Ibaraki 305-8572, Japan
| | - Ken-Ichiro Ishida
- Faculty of Life and Environmental Sciences, University of Tsukuba, Tsukuba, Ibaraki 305-8572, Japan
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15
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Saghaï A, Gutiérrez-Preciado A, Deschamps P, Moreira D, Bertolino P, Ragon M, López-García P. Unveiling microbial interactions in stratified mat communities from a warm saline shallow pond. Environ Microbiol 2017; 19:2405-2421. [PMID: 28489281 DOI: 10.1111/1462-2920.13754] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2017] [Revised: 04/02/2017] [Accepted: 04/03/2017] [Indexed: 01/09/2023]
Abstract
Modern phototrophic microbial mats are complex communities often used as analogs of major Precambrian ecosystems. Characterizing biotic, notably metabolic, interactions among different microbial mat members is essential to gain insights into the ecology and biogeochemistry of these systems. We applied 16S/18S rRNA metabarcoding approaches to characterize the structure of archaea, bacteria and protist communities from microbial mats collected along strong physicochemical (oxygen, salinity, temperature, depth) gradients in a shallow pond at the salar de Llamara (Chile). All mats were highly diverse, including members of virtually all known high-rank eukaryotic and prokaryotic taxa but also many novel lineages. Bacterial candidate divisions accounted for almost 50% of sequences in deeper mats, while Archaea represented up to 40% of sequences in some mat layers. Molecular phylogenetic analyses revealed six novel deeply divergent archaeal groups, along abundant and diverse Pacearchaeota and Woesearchaeota. Multivariate statistical analyses showed that local environmental conditions strongly influenced community composition. Co-occurrence network structure was markedly different between surface mats located in the oxygenated zone and mats located in transition and anoxic water layers. We identified potential biotic interactions between various high- and low-rank taxa. Notably, a strong positive correlation was observed between Lokiarchaeota and the poorly known candidate bacterial division TA06.
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Affiliation(s)
- Aurélien Saghaï
- Ecologie Systématique Evolution, CNRS, Université Paris-Sud, AgroParisTech, Université Paris-Saclay, Orsay, France
| | - Ana Gutiérrez-Preciado
- Ecologie Systématique Evolution, CNRS, Université Paris-Sud, AgroParisTech, Université Paris-Saclay, Orsay, France
| | - Philippe Deschamps
- Ecologie Systématique Evolution, CNRS, Université Paris-Sud, AgroParisTech, Université Paris-Saclay, Orsay, France
| | - David Moreira
- Ecologie Systématique Evolution, CNRS, Université Paris-Sud, AgroParisTech, Université Paris-Saclay, Orsay, France
| | - Paola Bertolino
- Ecologie Systématique Evolution, CNRS, Université Paris-Sud, AgroParisTech, Université Paris-Saclay, Orsay, France
| | - Marie Ragon
- Ecologie Systématique Evolution, CNRS, Université Paris-Sud, AgroParisTech, Université Paris-Saclay, Orsay, France
| | - Purificación López-García
- Ecologie Systématique Evolution, CNRS, Université Paris-Sud, AgroParisTech, Université Paris-Saclay, Orsay, France
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16
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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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17
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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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18
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Shiratori T, Ishida KI. A New Heterotrophic Cryptomonad: Hemiarma marina n. g., n. sp. J Eukaryot Microbiol 2016; 63:804-812. [PMID: 27218475 DOI: 10.1111/jeu.12327] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2016] [Revised: 05/05/2016] [Accepted: 05/06/2016] [Indexed: 11/28/2022]
Abstract
We report a new heterotrophic cryptomonad Hemiarma marina n. g., n. sp. that was collected from a seaweed sample from the Republic of Palau. In our molecular phylogenetic analyses using the small subunit ribosomal RNA gene, H. marina formed a clade with two marine environmental sequences, and the clade was placed as a sister lineage of the freshwater cryptomonad environmental clade CRY1. Alternatively, in the concatenated large and small subunit ribosomal RNA gene phylogeny, H. marina was placed as a sister lineage of Goniomonas. Light and electron microscopic observations showed that H. marina shares several ultrastructural features with cryptomonads, such as flattened mitochondrial cristae, a periplast cell covering, and ejectisomes that consist of two coiled ribbon structures. On the other hand, H. marina exhibited unique behaviors, such as attaching to substrates with its posterior flagellum and displaying a jumping motion. H. marina also had unique periplast arrangement and flagellar transitional region. On the basis of both molecular and morphological information, we concluded that H. marina should be treated as new genus and species of cryptomonads.
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Affiliation(s)
- Takashi Shiratori
- Graduate School of Life and Environmental Sciences, University of Tsukuba, Tsukuba, Ibaraki, 305-8572, Japan.
| | - Ken-Ichiro Ishida
- Faculty of Life and Environmental Sciences, University of Tsukuba, Tsukuba, Ibaraki, 305-8572, Japan
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19
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Shiratori T, Ishida KI. Trachyrhizium urniformis
n. g., n. sp., a Novel Marine Filose Thecate Amoeba Related to a Cercozoan Environmental Clade (Novel Clade 4). J Eukaryot Microbiol 2016; 63:722-731. [DOI: 10.1111/jeu.12319] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2015] [Revised: 04/05/2016] [Accepted: 04/05/2016] [Indexed: 11/30/2022]
Affiliation(s)
- Takashi Shiratori
- Graduate School of Life and Environmental Sciences; University of Tsukuba; Tsukuba Ibaraki 305-8572 Japan
| | - Ken-ichiro Ishida
- Faculty of Life and Environmental Sciences; University of Tsukuba; Tsukuba Ibaraki 305-8572 Japan
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20
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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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21
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Shiratori T, Nakayama T, Ishida KI. A New Deep-branching Stramenopile, Platysulcus tardus gen. nov., sp. nov. Protist 2015; 166:337-48. [PMID: 26070192 DOI: 10.1016/j.protis.2015.05.001] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2015] [Revised: 04/21/2015] [Accepted: 05/06/2015] [Indexed: 12/30/2022]
Abstract
A novel free-living heterotrophic stramenopile, Platysulcus tardus gen. nov., sp. nov. was isolated from sedimented detritus on a seaweed collected near the Ngeruktabel Island, Palau. P. tardus is a gliding flagellate with tubular mastigonemes on the anterior short flagellum and a wide, shallow ventral furrow. Although the flagellar apparatus of P. tardus is typical of stramenopiles, it shows novel ultrastructural combinations that are not applied to any groups of heterotrophic stramenopiles. Phylogenetic analysis using SSU rRNA genes revealed that P. tardus formed a clade with stramenopiles with high support. However, P. tardus did not form a subclade with any species or environmental sequences within the stramenopiles, and no close relative was suggested by the phylogenetic analysis. Therefore, we concluded that P. tardus should be treated as a new genus and species of stramenopiles and have proposed a new family, Platysulcidae fam. nov., for this phylogenetically distinct organism.
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Affiliation(s)
- Takashi Shiratori
- Graduate School of Life and Environmental Sciences, University of Tsukuba, Tsukuba, Ibaraki 305-8572, Japan
| | - Takeshi Nakayama
- Faculty of Life and Environmental Sciences, University of Tsukuba, Tsukuba, Ibaraki 305-8572, Japan
| | - Ken-ichiro Ishida
- Faculty of Life and Environmental Sciences, University of Tsukuba, Tsukuba, Ibaraki 305-8572, Japan.
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22
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Yubuki N, Pánek T, Yabuki A, Čepička I, Takishita K, Inagaki Y, Leander BS. Morphological Identities of Two Different Marine Stramenopile Environmental Sequence Clades: Bicosoeca kenaiensis
(Hilliard, 1971) and Cantina marsupialis
(Larsen and Patterson, 1990) gen. nov., comb. nov. J Eukaryot Microbiol 2015; 62:532-42. [DOI: 10.1111/jeu.12207] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2014] [Revised: 12/09/2014] [Accepted: 12/19/2014] [Indexed: 11/28/2022]
Affiliation(s)
- Naoji Yubuki
- The Departments of Botany and Zoology; Beaty Biodiversity Research Centre and Museum; University of British Columbia; Vancouver British Columbia V6T 1Z4 Canada
| | - Tomáš Pánek
- Department of Zoology; Faculty of Science; Charles University in Prague; Prague 128 44 Czech Republic
| | - Akinori Yabuki
- Japan Agency for Marine-Earth Science and Technology (JAMSTEC); Yokosuka Kanagawa 237-0061 Japan
| | - Ivan Čepička
- Department of Zoology; Faculty of Science; Charles University in Prague; Prague 128 44 Czech Republic
| | - Kiyotaka Takishita
- Japan Agency for Marine-Earth Science and Technology (JAMSTEC); Yokosuka Kanagawa 237-0061 Japan
| | - Yuji Inagaki
- Center for Computational Sciences and Graduate School of Life and Environmental Sciences; University of Tsukuba; Tsukuba Ibaraki 305-8577 Japan
| | - Brian S. Leander
- The Departments of Botany and Zoology; Beaty Biodiversity Research Centre and Museum; University of British Columbia; Vancouver British Columbia V6T 1Z4 Canada
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23
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Shiratori T, Yokoyama A, Ishida KI. Phylogeny, Ultrastructure, and Flagellar Apparatus of a New Marimonad Flagellate Abollifer globosa sp. nov. (Imbricatea, Cercozoa). Protist 2014; 165:808-24. [DOI: 10.1016/j.protis.2014.10.003] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2014] [Revised: 10/06/2014] [Accepted: 10/08/2014] [Indexed: 11/27/2022]
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24
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Pánek T, Simpson AG, Hampl V, Čepička I. Creneis carolina gen. et sp. nov. (Heterolobosea), a Novel Marine Anaerobic Protist with Strikingly Derived Morphology and Life Cycle. Protist 2014; 165:542-67. [DOI: 10.1016/j.protis.2014.05.005] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2014] [Revised: 05/05/2014] [Accepted: 05/28/2014] [Indexed: 11/29/2022]
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25
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Burki F. The eukaryotic tree of life from a global phylogenomic perspective. Cold Spring Harb Perspect Biol 2014; 6:a016147. [PMID: 24789819 DOI: 10.1101/cshperspect.a016147] [Citation(s) in RCA: 206] [Impact Index Per Article: 20.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
Molecular phylogenetics has revolutionized our knowledge of the eukaryotic tree of life. With the advent of genomics, a new discipline of phylogenetics has emerged: phylogenomics. This method uses large alignments of tens to hundreds of genes to reconstruct evolutionary histories. This approach has led to the resolution of ancient and contentious relationships, notably between the building blocks of the tree (the supergroups), and allowed to place in the tree enigmatic yet important protist lineages for understanding eukaryote evolution. Here, I discuss the pros and cons of phylogenomics and review the eukaryotic supergroups in light of earlier work that laid the foundation for the current view of the tree, including the position of the root. I conclude by presenting a picture of eukaryote evolution, summarizing the most recent progress in assembling the global tree.
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Affiliation(s)
- Fabien Burki
- Canadian Institute for Advanced Research, Department of Botany, University of British Columbia, Vancouver, British Columbia V6T 1Z4, Canada
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26
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Palpitomonas bilix represents a basal cryptist lineage: insight into the character evolution in Cryptista. Sci Rep 2014; 4:4641. [PMID: 24717814 PMCID: PMC3982174 DOI: 10.1038/srep04641] [Citation(s) in RCA: 55] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2013] [Accepted: 03/21/2014] [Indexed: 12/19/2022] Open
Abstract
Phylogenetic position of the marine biflagellate Palpitomonas bilix is intriguing, since several ultrastructural characteristics implied its evolutionary connection to Archaeplastida or Hacrobia. The origin and early evolution of these two eukaryotic assemblages have yet to be fully elucidated, and P. bilix may be a key lineage in tracing those groups' early evolution. In the present study, we analyzed a 'phylogenomic' alignment of 157 genes to clarify the position of P. bilix in eukaryotic phylogeny. In the 157-gene phylogeny, P. bilix was found to be basal to a clade of cryptophytes, goniomonads and kathablepharids, collectively known as Cryptista, which is proposed to be a part of the larger taxonomic assemblage Hacrobia. We here discuss the taxonomic assignment of P. bilix, and character evolution in Cryptista.
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27
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Heger TJ, Edgcomb VP, Kim E, Lukeš J, Leander BS, Yubuki N. A Resurgence in Field Research is Essential to Better Understand the Diversity, Ecology, and Evolution of Microbial Eukaryotes. J Eukaryot Microbiol 2014; 61:214-23. [DOI: 10.1111/jeu.12095] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2013] [Revised: 10/21/2013] [Accepted: 10/29/2013] [Indexed: 12/24/2022]
Affiliation(s)
- Thierry J. Heger
- Departments of Botany and Zoology; Beaty Biodiversity Research Centre and Museum; University of British Columbia; Vancouver BC V6T 1Z4 Canada
| | - Virginia P. Edgcomb
- Geology and Geophysics Department; Woods Hole Oceanographic Institution; Woods Hole Massachusetts 02543 USA
| | - Eunsoo Kim
- Division of Invertebrate Zoology; American Museum of Natural History; New York New York 10024 USA
| | - Julius Lukeš
- Institute of Parasitology; Biology Centre; Czech Academy of Sciences and Faculty of Science; University of South Bohemia; 37005 České Budějovice Czech Republic
| | - Brian S. Leander
- Departments of Botany and Zoology; Beaty Biodiversity Research Centre and Museum; University of British Columbia; Vancouver BC V6T 1Z4 Canada
| | - Naoji Yubuki
- Departments of Botany and Zoology; Beaty Biodiversity Research Centre and Museum; University of British Columbia; Vancouver BC V6T 1Z4 Canada
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28
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Lateral transfer of eukaryotic ribosomal RNA genes: an emerging concern for molecular ecology of microbial eukaryotes. ISME JOURNAL 2014; 8:1544-7. [PMID: 24451210 PMCID: PMC4069394 DOI: 10.1038/ismej.2013.252] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/29/2013] [Revised: 12/19/2013] [Accepted: 12/20/2013] [Indexed: 11/20/2022]
Abstract
Ribosomal RNA (rRNA) genes are widely utilized in depicting organismal diversity and distribution in a wide range of environments. Although a few cases of lateral transfer of rRNA genes between closely related prokaryotes have been reported, it remains to be reported from eukaryotes. Here, we report the first case of lateral transfer of eukaryotic rRNA genes. Two distinct sequences of the 18S rRNA gene were detected from a clonal culture of the stramenopile, Ciliophrys infusionum. One was clearly derived from Ciliophrys, but the other gene originated from a perkinsid alveolate. Genome-walking analyses revealed that this alveolate-type rRNA gene is immediately adjacent to two protein-coding genes (ubc12 and usp39), and the origin of both genes was shown to be a stramenopile (that is, Ciliophrys) in our phylogenetic analyses. These findings indicate that the alveolate-type rRNA gene is encoded on the Ciliophrys genome and that eukaryotic rRNA genes can be transferred laterally.
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29
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Yubuki N, Leander BS. Evolution of microtubule organizing centers across the tree of eukaryotes. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2013; 75:230-244. [PMID: 23398214 DOI: 10.1111/tpj.12145] [Citation(s) in RCA: 65] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/16/2012] [Revised: 02/04/2013] [Accepted: 02/05/2013] [Indexed: 05/28/2023]
Abstract
The architecture of eukaryotic cells is underpinned by complex arrrays of microtubules that stem from an organizing center, referred to as the MTOC. With few exceptions, MTOCs consist of two basal bodies that anchor flagellar axonemes and different configurations of microtubular roots. Variations in the structure of this cytoskeletal system, also referred to as the 'flagellar apparatus', reflect phylogenetic relationships and provide compelling evidence for inferring the overall tree of eukaryotes. However, reconstructions and subsequent comparisons of the flagellar apparatus are challenging, because these studies require sophisticated microscopy, spatial reasoning and detailed terminology. In an attempt to understand the unifying features of MTOCs and broad patterns of cytoskeletal homology across the tree of eukaryotes, we present a comprehensive overview of the eukaryotic flagellar apparatus within a modern molecular phylogenetic context. Specifically, we used the known cytoskeletal diversity within major groups of eukaryotes to infer the unifying features (ancestral states) for the flagellar apparatus in the Plantae, Opisthokonta, Amoebozoa, Stramenopiles, Alveolata, Rhizaria, Excavata, Cryptophyta, Haptophyta, Apusozoa, Breviata and Collodictyonidae. We then mapped these data onto the tree of eukaryotes in order to trace broad patterns of trait changes during the evolutionary history of the flagellar apparatus. This synthesis suggests that: (i) the most recent ancestor of all eukaryotes already had a complex flagellar apparatus, (ii) homologous traits associated with the flagellar apparatus have a punctate distribution across the tree of eukaryotes, and (iii) streamlining (trait losses) of the ancestral flagellar apparatus occurred several times independently in eukaryotes.
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Affiliation(s)
- Naoji Yubuki
- The Department of Botany, Beaty Biodiversity Research Centre and Museum, University of British Columbia, 6270 University Blvd, Vancouver, BC, V6T 1Z4, Canada.
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30
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Seenivasan R, Sausen N, Medlin LK, Melkonian M. Picomonas judraskeda gen. et sp. nov.: the first identified member of the Picozoa phylum nov., a widespread group of picoeukaryotes, formerly known as 'picobiliphytes'. PLoS One 2013; 8:e59565. [PMID: 23555709 PMCID: PMC3608682 DOI: 10.1371/journal.pone.0059565] [Citation(s) in RCA: 71] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2012] [Accepted: 02/19/2013] [Indexed: 01/21/2023] Open
Abstract
In 2007, a novel, putatively photosynthetic picoeukaryotic lineage, the ‘picobiliphytes’, with no known close eukaryotic relatives, was reported from 18S environmental clone library sequences and fluorescence in situ hybridization. Although single cell genomics later showed these organisms to be heterotrophic rather than photosynthetic, until now this apparently widespread group of pico-(or nano-)eukaryotes has remained uncultured and the organisms could not be formally recognized. Here, we describe Picomonas judraskeda gen. et sp. nov., from marine coastal surface waters, which has a ‘picobiliphyte’ 18S rDNA signature. Using vital mitochondrial staining and cell sorting by flow cytometry, a single cell-derived culture was established. The cells are biflagellate, 2.5–3.8×2–2.5 µm in size, lack plastids and display a novel stereotypic cycle of cell motility (described as the “jump, drag, and skedaddle”-cycle). They consist of two hemispherical parts separated by a deep cleft, an anterior part that contains all major cell organelles including the flagellar apparatus, and a posterior part housing vacuoles/vesicles and the feeding apparatus, both parts separated by a large vacuolar cisterna. From serial section analyses of cells, fixed at putative stages of the feeding cycle, it is concluded that cells are not bacterivorous, but feed on small marine colloids of less than 150 nm diameter by fluid-phase, bulk flow endocytosis. Based on the novel features of cell motility, ultrastructure and feeding, and their isolated phylogenetic position, we establish a new phylum, Picozoa, for Picomonas judraskeda, representing an apparently widespread and ecologically important group of heterotrophic picoeukaryotes, formerly known as ‘picobiliphytes’.
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Affiliation(s)
- Ramkumar Seenivasan
- Department of Botany, Cologne Biocenter, University of Cologne, Cologne, Germany.
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31
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Ultrastructure and Molecular Phylogeny of the Cryptomonad Goniomonas avonlea sp. nov. Protist 2013; 164:160-82. [DOI: 10.1016/j.protis.2012.10.002] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2012] [Revised: 09/02/2012] [Accepted: 10/03/2012] [Indexed: 11/19/2022]
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32
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Adl SM, Simpson AGB, Lane CE, Lukeš J, Bass D, Bowser SS, Brown MW, Burki F, Dunthorn M, Hampl V, Heiss A, Hoppenrath M, Lara E, Le Gall L, Lynn DH, McManus H, Mitchell EAD, Mozley-Stanridge SE, Parfrey LW, Pawlowski J, Rueckert S, Shadwick L, Shadwick L, Schoch CL, Smirnov A, Spiegel FW. The revised classification of eukaryotes. J Eukaryot Microbiol 2013; 59:429-93. [PMID: 23020233 DOI: 10.1111/j.1550-7408.2012.00644.x] [Citation(s) in RCA: 908] [Impact Index Per Article: 82.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
This revision of the classification of eukaryotes, which updates that of Adl et al. [J. Eukaryot. Microbiol. 52 (2005) 399], retains an emphasis on the protists and incorporates changes since 2005 that have resolved nodes and branches in phylogenetic trees. Whereas the previous revision was successful in re-introducing name stability to the classification, this revision provides a classification for lineages that were then still unresolved. The supergroups have withstood phylogenetic hypothesis testing with some modifications, but despite some progress, problematic nodes at the base of the eukaryotic tree still remain to be statistically resolved. Looking forward, subsequent transformations to our understanding of the diversity of life will be from the discovery of novel lineages in previously under-sampled areas and from environmental genomic information.
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Affiliation(s)
- Sina M Adl
- Department of Soil Science, University of Saskatchewan, Saskatoon, SK, S7N 5A8, Canada.
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Keeling PJ. The number, speed, and impact of plastid endosymbioses in eukaryotic evolution. ANNUAL REVIEW OF PLANT BIOLOGY 2013; 64:583-607. [PMID: 23451781 DOI: 10.1146/annurev-arplant-050312-120144] [Citation(s) in RCA: 271] [Impact Index Per Article: 24.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/19/2023]
Abstract
Plastids (chloroplasts) have long been recognized to have originated by endosymbiosis of a cyanobacterium, but their subsequent evolutionary history has proved complex because they have also moved between eukaryotes during additional rounds of secondary and tertiary endosymbioses. Much of this history has been revealed by genomic analyses, but some debates remain unresolved, in particular those relating to secondary red plastids of the chromalveolates, especially cryptomonads. Here, I examine several fundamental questions and assumptions about endosymbiosis and plastid evolution, including the number of endosymbiotic events needed to explain plastid diversity, whether the genetic contribution of the endosymbionts to the host genome goes far beyond plastid-targeted genes, and whether organelle origins are best viewed as a singular transition involving one symbiont or as a gradual transition involving a long line of transient food/symbionts. I also discuss a possible link between transporters and the evolution of protein targeting in organelle integration.
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Affiliation(s)
- Patrick J Keeling
- Canadian Institute for Advanced Research and Department of Botany, University of British Columbia, Vancouver, Canada V6T 1Z4.
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34
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Shiratori T, Yabuki A, Ishida KI. Esquamula lacrimiformis n. g., n. sp., a new member of thaumatomonads that lacks siliceous scales. J Eukaryot Microbiol 2012; 59:527-36. [PMID: 22742560 DOI: 10.1111/j.1550-7408.2012.00635.x] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2012] [Accepted: 05/07/2012] [Indexed: 11/29/2022]
Abstract
We report a new naked cercozoan flagellate, Esquamula lacrimiformis n. g., n. sp., collected from a sandy beach in Japan. Its cells were 4.5-11.3 μm in length and 3.9-8.8 μm in width and possess two unequal flagella. Cells move in a smooth gliding motion and have a trailing long posterior flagellum. Phylogenetic analyses with small and large subunit ribosomal RNA genes revealed that E. lacrimiformis forms a novel lineage within the Thaumatomonadida, the members of which are flagellates with siliceous scales. However, our light and electron microscopic observations indicated that E. lacrimiformis cells do not possess any siliceous structures. Furthermore, other morphological characteristics, such as the shape of the extrusomes and the structural arrangement of the microbody, were clearly different from those of previously described thaumatomonads. On the basis of a combination of these morphological observations and our phylogenetic analyses, we conclude that E. lacrimiformis should be treated as a new species of a new genus and placed into a new family, Esquamulidae n. fam., under Thaumatomonadida.
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Affiliation(s)
- Takashi Shiratori
- Graduate School of Life and Environmental Sciences, University of Tsukuba, 1-1-1 Tennoudai, Tsukuba, Ibaraki, 305-8572, Japan
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35
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Burki F, Okamoto N, Pombert JF, Keeling PJ. The evolutionary history of haptophytes and cryptophytes: phylogenomic evidence for separate origins. Proc Biol Sci 2012. [PMID: 22298847 DOI: 10.1098/rsbp.2011.2301] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/26/2023] Open
Abstract
An important missing piece in the puzzle of how plastids spread across the eukaryotic tree of life is a robust evolutionary framework for the host lineages. Four assemblages are known to harbour plastids derived from red algae and, according to the controversial chromalveolate hypothesis, these all share a common ancestry. Phylogenomic analyses have consistently shown that stramenopiles and alveolates are closely related, but haptophytes and cryptophytes remain contentious; they have been proposed to branch together with several heterotrophic groups in the newly erected Hacrobia. Here, we tested this question by producing a large expressed sequence tag dataset for the katablepharid Roombia truncata, one of the last hacrobian lineages for which genome-level data are unavailable, and combined this dataset with the recently completed genome of the cryptophyte Guillardia theta to build an alignment composed of 258 genes. Our analyses strongly support haptophytes as sister to the SAR group, possibly together with telonemids and centrohelids. We also confirmed the common origin of katablepharids and cryptophytes, but these lineages were not related to other hacrobians; instead, they branch with plants. Our study resolves the evolutionary position of haptophytes, an ecologically critical component of the oceans, and proposes a new hypothesis for the origin of cryptophytes.
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Affiliation(s)
- Fabien Burki
- Canadian Institute for Advanced Research, Department of Botany, University of British Columbia, Vancouver, British Columbia, Canada
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36
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Microheliella maris (Microhelida ord. n.), an Ultrastructurally Highly Distinctive New Axopodial Protist Species and Genus, and the Unity of Phylum Heliozoa. Protist 2012; 163:356-88. [DOI: 10.1016/j.protis.2011.10.001] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2011] [Accepted: 10/09/2011] [Indexed: 11/30/2022]
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37
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Cavalier-Smith T, Chao EE. Oxnerella micra sp. n. (Oxnerellidae fam. n.), a tiny naked centrohelid, and the diversity and evolution of heliozoa. Protist 2012; 163:574-601. [PMID: 22317961 DOI: 10.1016/j.protis.2011.12.005] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2011] [Revised: 12/22/2011] [Accepted: 12/19/2011] [Indexed: 01/30/2023]
Abstract
We describe a new tiny naked centrohelid heliozoan, Oxnerella micra, and sequenced its 18S and 28S rRNA genes. Its extremely slender axopodia have prominent extrusomes and are normally stretched across the substratum like those of many tiny granofilosean Cercozoa. Phylogenetic analysis of 18S rDNA shows that Oxnerella does not branch within any of the six known centrohelid families but very deeply in the order Pterocystida, between Choanocystidae and Pterocystidae; therefore we place it in a new family, Oxnerellidae. Oxnerella arose from ancestors with siliceous scales by losing them; as independently did Heterophryidae and Marophryidae, which replaced them by organic spicules, and Chlamydaster that is not truly naked but retains a mucilage coat and nests extremely shallowly within Pterocystidae. 28S rDNA has a group I intron. Concatenated Bayesian 18S/28S rRNA phylogeny shows centrohelids weakly as sisters to the naked non-centrohelid heliozoan Microheliella maris (Microhelida: Heliozoa). The centrohelid Marophrys marina possesses an elongation factor α-like (EFL) protein related to that of Polyplacocystis; Microheliella also has EFL. We also analysed Hsp90 and 18S rDNA sequences from 'Pinaciophora sp.' ATCC50355; they must be from a centrohelid, probably misidentified as Pinaciophora, the rDNA sequence branching deeply within Pterocystida. We reclassify two Polyplacocystis, Luffisphaera, Phaeodaria and Rotosphaerida.
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38
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Burki F, Okamoto N, Pombert JF, Keeling PJ. The evolutionary history of haptophytes and cryptophytes: phylogenomic evidence for separate origins. Proc Biol Sci 2012; 279:2246-54. [PMID: 22298847 DOI: 10.1098/rspb.2011.2301] [Citation(s) in RCA: 188] [Impact Index Per Article: 15.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023] Open
Abstract
An important missing piece in the puzzle of how plastids spread across the eukaryotic tree of life is a robust evolutionary framework for the host lineages. Four assemblages are known to harbour plastids derived from red algae and, according to the controversial chromalveolate hypothesis, these all share a common ancestry. Phylogenomic analyses have consistently shown that stramenopiles and alveolates are closely related, but haptophytes and cryptophytes remain contentious; they have been proposed to branch together with several heterotrophic groups in the newly erected Hacrobia. Here, we tested this question by producing a large expressed sequence tag dataset for the katablepharid Roombia truncata, one of the last hacrobian lineages for which genome-level data are unavailable, and combined this dataset with the recently completed genome of the cryptophyte Guillardia theta to build an alignment composed of 258 genes. Our analyses strongly support haptophytes as sister to the SAR group, possibly together with telonemids and centrohelids. We also confirmed the common origin of katablepharids and cryptophytes, but these lineages were not related to other hacrobians; instead, they branch with plants. Our study resolves the evolutionary position of haptophytes, an ecologically critical component of the oceans, and proposes a new hypothesis for the origin of cryptophytes.
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Affiliation(s)
- Fabien Burki
- Canadian Institute for Advanced Research, Department of Botany, University of British Columbia, Vancouver, British Columbia, Canada
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39
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Zhao S, Burki F, Bråte J, Keeling PJ, Klaveness D, Shalchian-Tabrizi K. Collodictyon--an ancient lineage in the tree of eukaryotes. Mol Biol Evol 2012; 29:1557-68. [PMID: 22319147 PMCID: PMC3351787 DOI: 10.1093/molbev/mss001] [Citation(s) in RCA: 78] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
Abstract
The current consensus for the eukaryote tree of life consists of several large assemblages (supergroups) that are hypothesized to describe the existing diversity. Phylogenomic analyses have shed light on the evolutionary relationships within and between supergroups as well as placed newly sequenced enigmatic species close to known lineages. Yet, a few eukaryote species remain of unknown origin and could represent key evolutionary forms for inferring ancient genomic and cellular characteristics of eukaryotes. Here, we investigate the evolutionary origin of the poorly studied protist Collodictyon (subphylum Diphyllatia) by sequencing a cDNA library as well as the 18S and 28S ribosomal DNA (rDNA) genes. Phylogenomic trees inferred from 124 genes placed Collodictyon close to the bifurcation of the “unikont” and “bikont” groups, either alone or as sister to the potentially contentious excavate Malawimonas. Phylogenies based on rDNA genes confirmed that Collodictyon is closely related to another genus, Diphylleia, and revealed a very low diversity in environmental DNA samples. The early and distinct origin of Collodictyon suggests that it constitutes a new lineage in the global eukaryote phylogeny. Collodictyon shares cellular characteristics with Excavata and Amoebozoa, such as ventral feeding groove supported by microtubular structures and the ability to form thin and broad pseudopods. These may therefore be ancient morphological features among eukaryotes. Overall, this shows that Collodictyon is a key lineage to understand early eukaryote evolution.
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Affiliation(s)
- Sen Zhao
- Microbial Evolution Research Group, Department of Biology, University of Oslo, Oslo, Norway
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40
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Gross J, Bhattacharya D, Pelletreau KN, Rumpho ME, Reyes-Prieto A. Secondary and Tertiary Endosymbiosis and Kleptoplasty. ADVANCES IN PHOTOSYNTHESIS AND RESPIRATION 2012. [DOI: 10.1007/978-94-007-2920-9_2] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
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41
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Ginger ML, Fritz-Laylin LK, Fulton C, Cande WZ, Dawson SC. Intermediary metabolism in protists: a sequence-based view of facultative anaerobic metabolism in evolutionarily diverse eukaryotes. Protist 2010; 161:642-71. [PMID: 21036663 PMCID: PMC3021972 DOI: 10.1016/j.protis.2010.09.001] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Protists account for the bulk of eukaryotic diversity. Through studies of gene and especially genome sequences the molecular basis for this diversity can be determined. Evident from genome sequencing are examples of versatile metabolism that go far beyond the canonical pathways described for eukaryotes in textbooks. In the last 2-3 years, genome sequencing and transcript profiling has unveiled several examples of heterotrophic and phototrophic protists that are unexpectedly well-equipped for ATP production using a facultative anaerobic metabolism, including some protists that can (Chlamydomonas reinhardtii) or are predicted (Naegleria gruberi, Acanthamoeba castellanii, Amoebidium parasiticum) to produce H(2) in their metabolism. It is possible that some enzymes of anaerobic metabolism were acquired and distributed among eukaryotes by lateral transfer, but it is also likely that the common ancestor of eukaryotes already had far more metabolic versatility than was widely thought a few years ago. The discussion of core energy metabolism in unicellular eukaryotes is the subject of this review. Since genomic sequencing has so far only touched the surface of protist diversity, it is anticipated that sequences of additional protists may reveal an even wider range of metabolic capabilities, while simultaneously enriching our understanding of the early evolution of eukaryotes.
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Affiliation(s)
- Michael L Ginger
- School of Health and Medicine, Division of Biomedical and Life Sciences, Lancaster University, Lancaster LA1 4YQ, UK.
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42
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Elias M. Patterns and processes in the evolution of the eukaryotic endomembrane system. Mol Membr Biol 2010; 27:469-89. [DOI: 10.3109/09687688.2010.521201] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
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