1
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Mills DB, Simister RL, Sehein TR, Hallam SJ, Sperling EA, Crowe SA. Constraining the oxygen requirements for modern microbial eukaryote diversity. Proc Natl Acad Sci U S A 2024; 121:e2303754120. [PMID: 38165897 PMCID: PMC10786294 DOI: 10.1073/pnas.2303754120] [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: 03/06/2023] [Accepted: 11/07/2023] [Indexed: 01/04/2024] Open
Abstract
Eukaryotes originated prior to the establishment of modern marine oxygen (O2) levels. According to the body fossil and lipid biomarker records, modern (crown) microbial eukaryote lineages began diversifying in the ocean no later than ~800 Ma. While it has long been predicted that increasing atmospheric O2 levels facilitated the early diversification of microbial eukaryotes, the O2 levels needed to permit this diversification remain unconstrained. Using time-resolved geochemical parameter and gene sequence information from a model marine oxygen minimum zone spanning a range of dissolved O2 levels and redox states, we show that microbial eukaryote taxonomic richness and phylogenetic diversity remain the same until O2 declines to around 2 to 3% of present atmospheric levels, below which these diversity metrics become significantly reduced. Our observations suggest that increasing O2 would have only directly promoted early crown-eukaryote diversity if atmospheric O2 was below 2 to 3% of modern levels when crown-eukaryotes originated and then later met or surpassed this range as crown-eukaryotes diversified. If atmospheric O2 was already consistently at or above 2 to 3% of modern levels by the time that crown-eukaryotes originated, then the subsequent diversification of modern microbial eukaryotes was not directly driven by atmospheric oxygenation.
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Affiliation(s)
- Daniel B. Mills
- Department of Earth and Environmental Sciences, Paleontology and Geobiology, Ludwig-Maximilians-Universität München, 80333Munich, Germany
- Department of Earth and Planetary Sciences, Stanford University, Stanford, CA94305
- The Penn State Extraterrestrial Intelligence Center, The Pennsylvania State University, University Park, PA16802
| | - Rachel L. Simister
- Department of Microbiology and Immunology, University of British Columbia, Vancouver, BCV6T 1Z4, Canada
| | - Taylor R. Sehein
- Department of Biological Sciences, Smith College, Northampton, MA01063
| | - Steven J. Hallam
- Department of Microbiology and Immunology, University of British Columbia, Vancouver, BCV6T 1Z4, Canada
- Genome Science and Technology Program, University of British Columbia, Vancouver, BCV6T 1Z4, Canada
- Graduate Program in Bioinformatics, University of British Columbia, Vancouver, BCV6T 1Z4, Canada
- Life Sciences Institute, University of British Columbia, Vancouver, BCV6T 1Z3, Canada
- Bradshaw Research Initiative for Minerals and Mining, University of British Columbia, Vancouver, BCV6T 1Z4, Canada
- Ecosystem Services, Commercialization Platforms and Entrepreneurship (ECOSCOPE) Training Program, University of British Columbia, Vancouver, BCV6T 1Z3, Canada
| | - Erik A. Sperling
- Department of Earth and Planetary Sciences, Stanford University, Stanford, CA94305
| | - Sean A. Crowe
- Department of Microbiology and Immunology, University of British Columbia, Vancouver, BCV6T 1Z4, Canada
- Department of Earth, Ocean, and Atmospheric Sciences, University of British Columbia, Vancouver, BCV6T 1Z4, Canada
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2
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Xu Z, Chen J, Li Y, Shekarriz E, Wu W, Chen B, Liu H. High Microeukaryotic Diversity in the Cold-Seep Sediment. MICROBIAL ECOLOGY 2023; 86:2003-2020. [PMID: 36973438 DOI: 10.1007/s00248-023-02212-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/29/2022] [Accepted: 03/22/2023] [Indexed: 06/18/2023]
Abstract
Microeukaryotic diversity, community structure, and their regulating mechanisms remain largely unclear in chemosynthetic ecosystems. Here, using high-throughput sequencing data of 18S rRNA genes, we explored microeukaryotic communities from the Haima cold seep in the northern South China Sea. We compared three distinct habitats: active, less active, and non-seep regions, with vertical layers (0-25 cm) from sediment cores. The results showed that seep regions harbored more abundant and diverse parasitic microeukaryotes (e.g., Apicomplexa and Syndiniales) as indicator species, compared to nearby non-seep region. Microeukaryotic community heterogeneity was larger between habitats than within habitat, and greatly increased when considering molecular phylogeny, suggesting the local diversification in cold-seep sediments. Microeukaryotic α-diversity at cold seeps was positively increased by metazoan richness and dispersal rate of microeukaryotes, while its β-diversity was promoted by heterogeneous selection mainly from metazoan communities (as potential hosts). Their combined effects led to the significant higher γ-diversity (i.e., total diversity in a region) at cold seeps than non-seep regions, suggesting cold-seep sediment as a hotspot for microeukaryotic diversity. Our study highlights the importance of microeukaryotic parasitism in cold-seep sediment and has implications for the roles of cold seep in maintaining and promoting marine biodiversity.
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Affiliation(s)
- Zhimeng Xu
- Southern Marine Science and Engineering Guangdong Laboratory (Guangzhou), Guangzhou, China
- Department of Ocean Science, The Hong Kong University of Science and Technology, Hong Kong, China
| | - Jiawei Chen
- Southern Marine Science and Engineering Guangdong Laboratory (Guangzhou), Guangzhou, China
- Department of Ocean Science, The Hong Kong University of Science and Technology, Hong Kong, China
| | - Yingdong Li
- Department of Ocean Science, The Hong Kong University of Science and Technology, Hong Kong, China
| | - Erfan Shekarriz
- Department of Ocean Science, The Hong Kong University of Science and Technology, Hong Kong, China
| | - Wenxue Wu
- State Key Laboratory of Marine Resource Utilization in South China Sea, Hainan University, Haikou, China
| | - Bingzhang Chen
- Southern Marine Science and Engineering Guangdong Laboratory (Guangzhou), Guangzhou, China
- Department of Mathematics and Statistics, University of Strathclyde, Glasgow, UK
| | - Hongbin Liu
- Southern Marine Science and Engineering Guangdong Laboratory (Guangzhou), Guangzhou, China.
- Department of Ocean Science, The Hong Kong University of Science and Technology, Hong Kong, China.
- Department of Ocean Science and Hong Kong Branch of the Southern Marine Science and Engineering Guangdong Laboratory (Guangzhou), The Hong Kong University of Science and Technology, Hong Kong, China.
- CAS-HKUST Sanya Joint Laboratory of Marine Science Research, Sanya, China.
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3
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Suter EA, Pachiadaki M, Taylor GT, Edgcomb VP. Eukaryotic Parasites Are Integral to a Productive Microbial Food Web in Oxygen-Depleted Waters. Front Microbiol 2022; 12:764605. [PMID: 35069470 PMCID: PMC8770914 DOI: 10.3389/fmicb.2021.764605] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2021] [Accepted: 12/13/2021] [Indexed: 01/04/2023] Open
Abstract
Oxygen-depleted water columns (ODWCs) host a diverse community of eukaryotic protists that change dramatically in composition over the oxic-anoxic gradient. In the permanently anoxic Cariaco Basin, peaks in eukaryotic diversity occurred in layers where dark microbial activity (chemoautotrophy and heterotrophy) were highest, suggesting a link between prokaryotic activity and trophic associations with protists. Using 18S rRNA gene sequencing, parasites and especially the obligate parasitic clade, Syndiniales, appear to be particularly abundant, suggesting parasitism is an important, but overlooked interaction in ODWC food webs. Syndiniales were also associated with certain prokaryotic groups that are often found in ODWCs, including Marinimicrobia and Marine Group II archaea, evocative of feedbacks between parasitic infection events, release of organic matter, and prokaryotic assimilative activity. In a network analysis that included all three domains of life, bacterial and archaeal taxa were putative bottleneck and hub species, while a large proportion of edges were connected to eukaryotic nodes. Inclusion of parasites resulted in a more complex network with longer path lengths between members. Together, these results suggest that protists, and especially protistan parasites, play an important role in maintaining microbial food web complexity, particularly in ODWCs, where protist diversity and microbial productivity are high, but energy resources are limited relative to euphotic waters.
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Affiliation(s)
- Elizabeth A Suter
- Biology, Chemistry & Environmental Studies Department, Center for Environmental Research and Coastal Oceans Monitoring, Molloy College, Rockville Centre, NY, United States.,School of Marine and Atmospheric Sciences, Stony Brook University, Stony Brook, NY, United States
| | - Maria Pachiadaki
- Department of Biology, Woods Hole Oceanographic Institution, Woods Hole, MA, United States
| | - Gordon T Taylor
- School of Marine and Atmospheric Sciences, Stony Brook University, Stony Brook, NY, United States
| | - Virginia P Edgcomb
- Department of Geology & Geophysics, Woods Hole Oceanographic Institution, Woods Hole, MA, United States
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4
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Fuchsman CA, Cherubini L, Hays MD. An analysis of protists in Pacific oxygen deficient zones: implications for Prochlorococcus and N 2 -producing bacteria. Environ Microbiol 2022; 24:1790-1804. [PMID: 34995411 DOI: 10.1111/1462-2920.15893] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2021] [Revised: 12/27/2021] [Accepted: 12/29/2021] [Indexed: 11/26/2022]
Abstract
Ocean oxygen deficient zones (ODZs) host 30%-50% of marine N2 production. Cyanobacteria photosynthesizing in the ODZ create a secondary chlorophyll maximum and provide organic matter to N2 -producing bacteria. This chlorophyll maximum is thought to occur due to reduced grazing in anoxic waters. We first examine ODZ protists with long amplicon reads. We then use non-primer-based methods to examine the composition and relative abundance of protists in metagenomes from the Eastern Tropical North and South Pacific ODZs and compare these data to the oxic Hawaii Ocean Time-series (HOT) in the North Pacific. We identify and quantify protists in proportion to the total microbial community. From metagenomic data, we see a large drop in abundance of fungi and protists such as choanoflagellates, radiolarians, cercozoa and ciliates in the ODZs but not in the oxic mesopelagic at HOT. Diplonemid euglenozoa were the only protists that increased in the ODZ. Dinoflagellates and foraminifera reads were also present in the ODZ though less abundant compared to oxic waters. Denitrification has been found in foraminifera but not yet in dinoflagellates. DNA techniques cannot separate dinoflagellate cells and cysts. Metagenomic analysis found taxonomic groups missed by amplicon sequencing and identified trends in abundance.
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Affiliation(s)
- Clara A Fuchsman
- University of Maryland Center for Environmental Science Horn Point Laboratory, Cambridge, MD, 21613, USA
| | - Luca Cherubini
- Maryland Sea Grant College, College Park, MD, 20740, USA
| | - Matthew D Hays
- University of Maryland Center for Environmental Science Horn Point Laboratory, Cambridge, MD, 21613, USA
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5
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Extremophilic Microorganisms in Central Europe. Microorganisms 2021; 9:microorganisms9112326. [PMID: 34835450 PMCID: PMC8620676 DOI: 10.3390/microorganisms9112326] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2021] [Revised: 11/04/2021] [Accepted: 11/05/2021] [Indexed: 11/17/2022] Open
Abstract
Extremophiles inhabit a wide variety of environments. Here we focus on extremophiles in moderate climates in central Europe, and particularly in Slovenia. Although multiple types of stress often occur in the same habitat, extremophiles are generally combined into groups according to the main stressor to which they are adapted. Several types of extremophiles, e.g., oligotrophs, are well represented and diverse in subsurface environments and karst regions. Psychrophiles thrive in ice caves and depressions with eternal snow and ice, with several globally distributed snow algae and psychrophilic bacteria that have been discovered in alpine glaciers. However, this area requires further research. Halophiles thrive in salterns while thermophiles inhabit thermal springs, although there is little data on such microorganisms in central Europe, despite many taxa being found globally. This review also includes the potential use of extremophiles in biotechnology and bioremediation applications.
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6
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Long AM, Jurgensen SK, Petchel AR, Savoie ER, Brum JR. Microbial Ecology of Oxygen Minimum Zones Amidst Ocean Deoxygenation. Front Microbiol 2021; 12:748961. [PMID: 34777296 PMCID: PMC8578717 DOI: 10.3389/fmicb.2021.748961] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2021] [Accepted: 10/06/2021] [Indexed: 01/05/2023] Open
Abstract
Oxygen minimum zones (OMZs) have substantial effects on the global ecology and biogeochemical processes of marine microbes. However, the diversity and activity of OMZ microbes and their trophic interactions are only starting to be documented, especially in regard to the potential roles of viruses and protists. OMZs have expanded over the past 60 years and are predicted to expand due to anthropogenic climate change, furthering the need to understand these regions. This review summarizes the current knowledge of OMZ formation, the biotic and abiotic factors involved in OMZ expansion, and the microbial ecology of OMZs, emphasizing the importance of bacteria, archaea, viruses, and protists. We describe the recognized roles of OMZ microbes in carbon, nitrogen, and sulfur cycling, the potential of viruses in altering host metabolisms involved in these cycles, and the control of microbial populations by grazers and viruses. Further, we highlight the microbial community composition and roles of these organisms in oxic and anoxic depths within the water column and how these differences potentially inform how microbial communities will respond to deoxygenation. Additionally, the current literature on the alteration of microbial communities by other key climate change parameters such as temperature and pH are considered regarding how OMZ microbes might respond to these pressures. Finally, we discuss what knowledge gaps are present in understanding OMZ microbial communities and propose directions that will begin to close these gaps.
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Affiliation(s)
- Andrew M. Long
- Department of Oceanography and Coastal Sciences, Louisiana State University, Baton Rouge, LA, United States
| | | | | | | | - Jennifer R. Brum
- Department of Oceanography and Coastal Sciences, Louisiana State University, Baton Rouge, LA, United States
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7
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Small pigmented eukaryote assemblages of the western tropical North Atlantic around the Amazon River plume during spring discharge. Sci Rep 2021; 11:16200. [PMID: 34376772 PMCID: PMC8355221 DOI: 10.1038/s41598-021-95676-2] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2021] [Accepted: 07/26/2021] [Indexed: 02/07/2023] Open
Abstract
Small pigmented eukaryotes (⩽ 5 µm) are an important, but overlooked component of global marine phytoplankton. The Amazon River plume delivers nutrients into the oligotrophic western tropical North Atlantic, shades the deeper waters, and drives the structure of microphytoplankton (> 20 µm) communities. For small pigmented eukaryotes, however, diversity and distribution in the region remain unknown, despite their significant contribution to open ocean primary production and other biogeochemical processes. To investigate how habitats created by the Amazon river plume shape small pigmented eukaryote communities, we used high-throughput sequencing of the 18S ribosomal RNA genes from up to five distinct small pigmented eukaryote cell populations, identified and sorted by flow cytometry. Small pigmented eukaryotes dominated small phytoplankton biomass across all habitat types, but the population abundances varied among stations resulting in a random distribution. Small pigmented eukaryote communities were consistently dominated by Chloropicophyceae (0.8-2 µm) and Bacillariophyceae (0.8-3.5 µm), accompanied by MOCH-5 at the surface or by Dinophyceae at the chlorophyll maximum. Taxonomic composition only displayed differences in the old plume core and at one of the plume margin stations. Such results reflect the dynamic interactions of the plume and offshore oceanic waters and suggest that the resident small pigmented eukaryote diversity was not strongly affected by habitat types at this time of the year.
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8
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Kostygov AY, Karnkowska A, Votýpka J, Tashyreva D, Maciszewski K, Yurchenko V, Lukeš J. Euglenozoa: taxonomy, diversity and ecology, symbioses and viruses. Open Biol 2021; 11:200407. [PMID: 33715388 PMCID: PMC8061765 DOI: 10.1098/rsob.200407] [Citation(s) in RCA: 77] [Impact Index Per Article: 25.7] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
Euglenozoa is a species-rich group of protists, which have extremely diverse lifestyles and a range of features that distinguish them from other eukaryotes. They are composed of free-living and parasitic kinetoplastids, mostly free-living diplonemids, heterotrophic and photosynthetic euglenids, as well as deep-sea symbiontids. Although they form a well-supported monophyletic group, these morphologically rather distinct groups are almost never treated together in a comparative manner, as attempted here. We present an updated taxonomy, complemented by photos of representative species, with notes on diversity, distribution and biology of euglenozoans. For kinetoplastids, we propose a significantly modified taxonomy that reflects the latest findings. Finally, we summarize what is known about viruses infecting euglenozoans, as well as their relationships with ecto- and endosymbiotic bacteria.
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Affiliation(s)
- Alexei Y Kostygov
- Life Science Research Centre, Faculty of Science, University of Ostrava, Ostrava, Czech Republic.,Zoological Institute, Russian Academy of Sciences, St Petersburg, Russia
| | - Anna Karnkowska
- Institute of Evolutionary Biology, Faculty of Biology, Biological and Chemical Research Centre, University of Warsaw, Warsaw, Poland
| | - Jan Votýpka
- Institute of Parasitology, Czech Academy of Sciences, České Budějovice (Budweis), Czech Republic.,Department of Parasitology, Faculty of Science, Charles University, Prague, Czech Republic
| | - Daria Tashyreva
- Institute of Parasitology, Czech Academy of Sciences, České Budějovice (Budweis), Czech Republic
| | - Kacper Maciszewski
- Institute of Evolutionary Biology, Faculty of Biology, Biological and Chemical Research Centre, University of Warsaw, Warsaw, Poland
| | - Vyacheslav Yurchenko
- Life Science Research Centre, Faculty of Science, University of Ostrava, Ostrava, Czech Republic.,Martsinovsky Institute of Medical Parasitology, Tropical and Vector Borne Diseases, Sechenov University, Moscow, Russia
| | - Julius Lukeš
- Institute of Parasitology, Czech Academy of Sciences, České Budějovice (Budweis), Czech Republic.,Faculty of Sciences, University of South Bohemia, České Budějovice (Budweis), Czech Republic
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9
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Lax G, Kolisko M, Eglit Y, Lee WJ, Yubuki N, Karnkowska A, Leander BS, Burger G, Keeling PJ, Simpson AGB. Multigene phylogenetics of euglenids based on single-cell transcriptomics of diverse phagotrophs. Mol Phylogenet Evol 2021; 159:107088. [PMID: 33545276 DOI: 10.1016/j.ympev.2021.107088] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2020] [Revised: 01/24/2021] [Accepted: 01/26/2021] [Indexed: 12/22/2022]
Abstract
Euglenids are a well-known group of single-celled eukaryotes, with phototrophic, osmotrophic and phagotrophic members. Phagotrophs represent most of the phylogenetic diversity of euglenids, and gave rise to the phototrophs and osmotrophs, but their evolutionary relationships are poorly understood. Symbiontids, in contrast, are anaerobes that are alternatively inferred to be derived euglenids, or a separate euglenozoan group. Most phylogenetic studies of euglenids have examined the SSU rDNA only, which is often highly divergent. Also, many phagotrophic euglenids (and symbiontids) are uncultured, restricting collection of other molecular data. We generated transcriptome data for 28 taxa, mostly using a single-cell approach, and conducted the first multigene phylogenetic analyses of euglenids to include phagotrophs and symbiontids. Euglenids are recovered as monophyletic, with symbiontids forming an independent branch within Euglenozoa. Spirocuta, the clade of flexible euglenids that contains both the phototrophs (Euglenophyceae) and osmotrophs (Aphagea), is robustly resolved, with the ploeotid Olkasia as its sister group, forming the new taxon Olkaspira. Ploeotids are paraphyletic, although Ploeotiidae (represented by Ploeotia spp.), Lentomonas, and Keelungia form a robust clade (new taxon Alistosa). Petalomonadida branches robustly as sister to other euglenids in outgroup-rooted analyses. Within Spirocuta, Euglenophyceae is a robust clade that includes Rapaza, and Anisonemia is a well-supported monophyletic group containing Anisonemidae (Anisonema and Dinema spp.), 'Heteronema II' (represented by H. vittatum), and a clade of Neometanema plus Aphagea. Among 'peranemid' phagotrophs, Chasmostoma branches with included Urceolus, and Peranema with the undescribed 'Jenningsia II', while other relationships are weakly supported and consequently the closest sister group to Euglenophyceae remains unresolved. Our results are inconsistent with recent inferences that Entosiphon is the evolutionarily pivotal sister either to other euglenids, or to Spirocuta. At least three transitions between posterior and anterior flagellar gliding occurred in euglenids, with the phylogenetic positions and directions of those transitions remaining ambiguous.
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Affiliation(s)
- G Lax
- Department of Biology, and Centre for Comparative Genomics and Evolutionary Bioinformatics, Dalhousie University, Halifax, Canada; Department of Botany, University of British Columbia, Vancouver, Canada(1)
| | - M Kolisko
- Institute of Parasitology, Biology Centre, Czech Academy of Sciences, České Budějovice, Czech Republic
| | - Y Eglit
- Department of Biology, and Centre for Comparative Genomics and Evolutionary Bioinformatics, Dalhousie University, Halifax, Canada
| | - W J Lee
- Department of Environment and Energy Engineering, Kyungnam University, Changwon, Republic of Korea
| | - N Yubuki
- Unité d'Ecologie Systématique et Evolution, CNRS, Université Paris-Saclay, Orsay, France; Department of Zoology, University of British Columbia, Vancouver, Canada
| | - A Karnkowska
- Institute of Evolutionary Biology, Faculty of Biology, University of Warsaw, Poland
| | - B S Leander
- Department of Zoology, University of British Columbia, Vancouver, Canada
| | - G Burger
- Robert-Cedergren Centre for Bioinformatics and Genomics, Biochemistry Department, Université de Montréal, Montréal, Canada
| | - P J Keeling
- Department of Botany, University of British Columbia, Vancouver, Canada(1)
| | - A G B Simpson
- Department of Biology, and Centre for Comparative Genomics and Evolutionary Bioinformatics, Dalhousie University, Halifax, Canada.
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10
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Lax G, Simpson AGB. The Molecular Diversity of Phagotrophic Euglenids Examined Using Single-cell Methods. Protist 2020; 171:125757. [PMID: 33126020 DOI: 10.1016/j.protis.2020.125757] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2020] [Revised: 07/29/2020] [Accepted: 08/05/2020] [Indexed: 01/16/2023]
Abstract
Euglenids are a diverse group of euglenozoan flagellates that includes phototrophs, osmotrophs, and phagotrophs. Despite making up most of the phylogenetic diversity of euglenids, phagotrophs remain understudied, and recent work has focused on 'deep-branching' groups. Spirocuta is the large clade encompassing all flexible euglenids including the phototroph and primary osmotroph clades, plus various phagotrophs. Understanding the phylogenetic diversity of phagotrophic spirocutes is crucial for tracing euglenid evolution, including how phototrophs arose. We used single-cell approaches to greatly increase sampling of SSU rDNA for phagotrophic euglenids, particularly spirocutes, including the first sequences from Urceolus, Jenningsia, Chasmostoma, and Sphenomonas, and expanded coverage for Dinema and Heteronema sensu lato, amongst others. Urceolus monophyly is unconfirmed. Organisms referred to Jenningsia form two distinct clades. Heteronema vittatum and similar cells branch separately from Heteronema (c.f.) globuliferum and Teloprocta/Heteronema scaphurum, while Dinema appears as 2-3 clades. Sphenomonas is monophyletic and the deepest branch within Petalomonadida. The census of genera markedly underestimates the phylogenetic diversity of phagotrophs, but taxonomic restraint is necessary when sequences are not available from type species or reasonable surrogates. SSU rDNA phylogenies do not resolve most deep relationships within Spirocuta, but identify units of diversity to sample in future multigene analyses.
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Affiliation(s)
- Gordon Lax
- Department of Biology, and Centre for Comparative Genomics and Evolutionary Bioinformatics, Dalhousie University, Halifax, NS, Canada
| | - Alastair G B Simpson
- Department of Biology, and Centre for Comparative Genomics and Evolutionary Bioinformatics, Dalhousie University, Halifax, NS, Canada.
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11
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Liu Y, He H, Fu L, Liu Q, Yang Z, Zhen Y. Environmental DNA Sequencing Reveals a Highly Complex Eukaryote Community in Sansha Yongle Blue Hole, Xisha, South China Sea. Microorganisms 2019; 7:microorganisms7120624. [PMID: 31795180 PMCID: PMC6956243 DOI: 10.3390/microorganisms7120624] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2019] [Revised: 11/25/2019] [Accepted: 11/25/2019] [Indexed: 01/06/2023] Open
Abstract
We report an Illumina high-throughput sequencing protocol of eukaryotic microbes in the world’s deepest marine blue hole, Sansha Yongle Blue Hole, Xisha, South China Sea. The variable V9 region of small subunit (SSU) rDNA, was sequenced using this approach from the waters of blue hole and outer reef slope. 917,771 unique eukaryotic 18S rRNA gene sequences and 6093 operational taxonomic units (OTUs) were identified. Significant differences in the eukaryotic composition were observed between the blue hole and outer reef slope, and the richness in the blue hole was much higher than that in the outer reef slope. The richness and diversity of eukaryotes in the blue hole were both lowest at 60 m and highest at 100 m depth. Eukaryotic microalgae assemblages dominated by Dinophyceae were the most abundant in the 10–20 m water column in the hole. Fauna was the main group at and below a depth of 60 m, where Araneae and Cyclopoida were dominant in the 60 m and 80 m water layer, respectively. There was a large number of Entoprocta at a depth of 180 m in the hole, where little oxygen was detected. Turbidity and nitrite concentration had a significant effect on the eukaryote community structure (p < 0.01).
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Affiliation(s)
- Yueteng Liu
- Key Laboratory of Marine Environment and Ecology, Ministry of Education, Qingdao 266100, China;
- College of Environmental Science and Engineering, Ocean University of China, Qingdao 266100, China
| | - Hui He
- College of Marine Life Science, Ocean University of China, Qingdao 266003, China; (H.H.); (Q.L.)
| | - Liang Fu
- Sansha Trackline Institute of Coral Reef Environment Protection, Sansha 573199, China;
| | - Qian Liu
- College of Marine Life Science, Ocean University of China, Qingdao 266003, China; (H.H.); (Q.L.)
| | - Zuosheng Yang
- College of Marine Geosciences, Ocean University of China, Qingdao 266100, China;
| | - Yu Zhen
- Key Laboratory of Marine Environment and Ecology, Ministry of Education, Qingdao 266100, China;
- College of Environmental Science and Engineering, Ocean University of China, Qingdao 266100, China
- Laboratory for Marine Ecology and Environmental Science, Qingdao National Laboratory for Marine Science and Technology, Qingdao 266237, China
- Correspondence: ; Tel.: +86-532-66781940
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12
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The potential of sedimentary ancient DNA for reconstructing past sea ice evolution. ISME JOURNAL 2019; 13:2566-2577. [PMID: 31235841 PMCID: PMC6776040 DOI: 10.1038/s41396-019-0457-1] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/15/2019] [Revised: 05/02/2019] [Accepted: 05/24/2019] [Indexed: 11/24/2022]
Abstract
Sea ice is a crucial component of the Arctic climate system, yet the tools to document the evolution of sea ice conditions on historical and geological time scales are few and have limitations. Such records are essential for documenting and understanding the natural variations in Arctic sea ice extent. Here we explore sedimentary ancient DNA (aDNA), as a novel tool that unlocks and exploits the genetic (eukaryote) biodiversity preserved in marine sediments specifically for past sea ice reconstructions. Although use of sedimentary aDNA in paleoceanographic and paleoclimatic studies is still in its infancy, we use here metabarcoding and single-species quantitative DNA detection methods to document the sea ice conditions in a Greenland Sea marine sediment core. Metabarcoding has allowed identifying biodiversity changes in the geological record back to almost ~100,000 years ago that were related to changing sea ice conditions. Detailed bioinformatic analyses on the metabarcoding data revealed several sea-ice-associated taxa, most of which previously unknown from the fossil record. Finally, we quantitatively traced one known sea ice dinoflagellate in the sediment core. We show that aDNA can be recovered from deep-ocean sediments with generally oxic bottom waters and that past sea ice conditions can be documented beyond instrumental time scales. Our results corroborate sea ice reconstructions made by traditional tools, and thus demonstrate the potential of sedimentary aDNA, focusing primarily on microbial eukaryotes, as a new tool to better understand sea ice evolution in the climate system.
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Pasulka A, Hu SK, Countway PD, Coyne KJ, Cary SC, Heidelberg KB, Caron DA. SSU-rRNA Gene Sequencing Survey of Benthic Microbial Eukaryotes from Guaymas Basin Hydrothermal Vent. J Eukaryot Microbiol 2019; 66:637-653. [PMID: 30620427 DOI: 10.1111/jeu.12711] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2018] [Revised: 12/09/2018] [Accepted: 12/16/2018] [Indexed: 12/21/2022]
Abstract
Microbial eukaryotes have important roles in marine food webs, but their diversity and activities in hydrothermal vent ecosystems are poorly characterized. In this study, we analyzed microbial eukaryotic communities associated with bacterial (Beggiatoa) mats in the 2,000 m deep-sea Guaymas Basin hydrothermal vent system using 18S rRNA gene high-throughput sequencing of the V4 region. We detected 6,954 distinct Operational Taxonomic Units (OTUs) across various mat systems. Of the sequences that aligned with known protistan phylotypes, most were affiliated with alveolates (especially dinoflagellates and ciliates) and cercozoans. OTU richness and community structure differed among sediment habitats (e.g. different mat types and cold sediments away from mats). Additionally, full-length 18S rRNA genes amplified and cloned from single cells revealed the identities of some of the most commonly encountered, active ciliates in this hydrothermal vent ecosystem. Observations and experiments were also conducted to demonstrate that ciliates were trophically active and ingesting fluorescent bacteria or Beggiatoa trichomes. Our work suggests that the active and diverse protistan community at the Guaymas Basin hydrothermal vent ecosystem likely consumes substantial amounts of bacterial biomass, and that the different habitats, often defined by distances of just a few 10s of cm, select for particular assemblages and levels of diversity.
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Affiliation(s)
- Alexis Pasulka
- Biological Sciences Department, California Polytechnic State University, 1 Grand Avenue, San Luis Obispo, California, USA
| | - Sarah K Hu
- Department of Biological Sciences, University of Southern California, 3616 Trousdale Parkway, AHF 301 Los Angeles, Los Angeles, California, USA
| | - Peter D Countway
- Bigelow Laboratory for Ocean Sciences, 60 Bigelow Drive, East Boothbay, Maine, USA
| | - Kathryn J Coyne
- College of Earth, Ocean, and Environment, University of Delaware, 700 Pilottown Road, Lewes, Delaware, USA
| | - Stephen C Cary
- Department of Biological Sciences, The University of Waikato, Private Bag 3105, Hamilton, New Zealand
| | - Karla B Heidelberg
- Department of Biological Sciences, University of Southern California, 3616 Trousdale Parkway, AHF 301 Los Angeles, Los Angeles, California, USA
| | - David A Caron
- Department of Biological Sciences, University of Southern California, 3616 Trousdale Parkway, AHF 301 Los Angeles, Los Angeles, California, USA
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14
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Yubuki N, Leander BS. Diversity and Evolutionary History of the Symbiontida (Euglenozoa). Front Ecol Evol 2018. [DOI: 10.3389/fevo.2018.00100] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
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15
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Anoxic ecosystems and early eukaryotes. Emerg Top Life Sci 2018; 2:299-309. [DOI: 10.1042/etls20170162] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2018] [Revised: 05/22/2018] [Accepted: 05/24/2018] [Indexed: 01/27/2023]
Abstract
Through much of the Proterozoic Eon (2.5–0.54 billion years ago, Ga), oceans were dominantly anoxic. It is often assumed that this put a brake on early eukaryote diversification because eukaryotes lived only in oxygenated habitats, which were restricted to surface waters and benthic environments near cyanobacterial mats. Studies of extant microbial eukaryotes show, however, that they are diverse and abundant in anoxic (including sulfidic) environments, often through partnerships with endo- and ectosymbiotic bacteria and archaea. Though the last common ancestor of extant eukaryotes was capable of aerobic respiration, we propose that at least some, and perhaps many, early eukaryotes were adapted to anoxic settings, and outline a way to test this with the microfossil and redox-proxy record in Proterozoic shales. This hypothesis might explain the mismatch between the record of eukaryotic body fossils, which extends back to >1.6 Ga, and the record of sterane biomarkers, which become diverse and abundant only after 659 Ma, as modern eukaryotes adapted to anoxic habitats do not make sterols (sterane precursors). In addition, an anoxic habitat might make sense for several long-ranging (>800 million years) and globally widespread eukaryotic taxa, which disappear in the late Neoproterozoic around the time oxic environments are thought to have become more widespread.
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16
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Orsi WD, Wilken S, Del Campo J, Heger T, James E, Richards TA, Keeling PJ, Worden AZ, Santoro AE. Identifying protist consumers of photosynthetic picoeukaryotes in the surface ocean using stable isotope probing. Environ Microbiol 2018; 20:815-827. [PMID: 29215213 DOI: 10.1111/1462-2920.14018] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2017] [Revised: 11/26/2017] [Accepted: 11/26/2017] [Indexed: 11/29/2022]
Abstract
Photosynthetic picoeukaryotes contribute a significant fraction of primary production in the upper ocean. Micromonas pusilla is an ecologically relevant photosynthetic picoeukaryote, abundantly and widely distributed in marine waters. Grazing by protists may control the abundance of picoeukaryotes such as M. pusilla, but the diversity of the responsible grazers is poorly understood. To identify protists consuming photosynthetic picoeukaryotes in a productive North Pacific Ocean region, we amended seawater with living 15 N, 13 C-labelled M. pusilla cells in a 24-h replicated bottle experiment. DNA stable isotope probing, combined with high-throughput sequencing of V4 hypervariable regions from 18S rRNA gene amplicons (Tag-SIP), identified 19 operational taxonomic units (OTUs) of microbial eukaryotes that consumed M. pusilla. These OTUs were distantly related to cultured taxa within the dinoflagellates, ciliates, stramenopiles (MAST-1C and MAST-3 clades) and Telonema flagellates, thus, far known only from their environmental 18S rRNA gene sequences. Our discovery of eukaryotic prey consumption by MAST cells confirms that their trophic role in marine microbial food webs includes grazing upon picoeukaryotes. Our study provides new experimental evidence directly linking the genetic identity of diverse uncultivated microbial eukaryotes to the consumption of picoeukaryotic phytoplankton in the upper ocean.
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Affiliation(s)
- William D Orsi
- Horn Point Laboratory, University of Maryland Center for Environmental Science, Cambridge, MD 21613, USA
| | - Susanne Wilken
- Monterey Bay Aquarium Research Institute, Moss Landing, CA 95039, USA
| | - Javier Del Campo
- Department of Botany, University of British Columbia, Vancouver, British Columbia, Canada
| | - Thierry Heger
- Department of Botany, University of British Columbia, Vancouver, British Columbia, Canada
| | - Erick James
- Department of Botany, University of British Columbia, Vancouver, British Columbia, Canada
| | - Thomas A Richards
- Department of Biosciences, University of Exeter, Geoffrey Pope Building, Exeter, EX4 4QD, UK
| | - Patrick J Keeling
- Department of Botany, University of British Columbia, Vancouver, British Columbia, Canada
| | | | - Alyson E Santoro
- Horn Point Laboratory, University of Maryland Center for Environmental Science, Cambridge, MD 21613, USA
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17
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Filker S, Forster D, Weinisch L, Mora-Ruiz M, González B, Farías ME, Rosselló-Móra R, Stoeck T. Transition boundaries for protistan species turnover in hypersaline waters of different biogeographic regions. Environ Microbiol 2017; 19:3186-3200. [PMID: 28574222 DOI: 10.1111/1462-2920.13805] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2016] [Accepted: 05/26/2017] [Indexed: 11/28/2022]
Abstract
The identification of environmental barriers which govern species distribution is a fundamental concern in ecology. Even though salt was previously identified as a major transition boundary for micro- and macroorganisms alike, the salinities causing species turnover in protistan communities are unknown. We investigated 4.5 million high-quality protistan metabarcodes (V4 region of the SSU rDNA) obtained from 24 shallow salt ponds (salinities 4%-44%) from South America and Europe. Statistical analyses of protistan community profiles identified four salinity classes, which strongly selected for different protistan communities: 4-9%, 14-24%, 27-36% and 38-44%. The proportion of organisms unknown to science is highest in the 14-24% salinity class, showing that environments within this salinity range are an unappreciated reservoir of as yet undiscovered organisms. Distinct higher-rank taxon groups dominated in the four salinity classes in terms of diversity. As increasing salinities require different cellular responses to cope with salt, our results suggest that different evolutionary lineages of protists have evolved distinct haloadaptation strategies. Salinity appears to be a stronger selection factor for the structuring of protistan communities than geography. Yet, we find a higher degree of endemism in shallow salt ponds compared with less isolated ecosystems such as the open ocean. Thus, rules for biogeographic structuring of protistan communities are not universal, but depend on the ecosystem under consideration.
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Affiliation(s)
- Sabine Filker
- Department of Molecular Ecology, University of Kaiserslautern, 67663, Kaiserslautern, Germany
| | - Dominik Forster
- Department of Ecology, University of Kaiserslautern, 67663, Kaiserslautern, Germany
| | - Lea Weinisch
- Department of Ecology, University of Kaiserslautern, 67663, Kaiserslautern, Germany
| | - Merit Mora-Ruiz
- Marine Microbiology Group, Department of Ecology and Marine Resources, Institut Mediterrani d'Estudis Avançats, IMEDEA (CSIC-UIB), 07190 Esporles, Illes Balears, Spain
| | - Bernardo González
- Facultad de Ingeniería y Ciencias, Universidad Adolfo Ibáñez - Center of Applied Ecology and Sustainability, Santiago de Chile, Chile
| | - María Eugenia Farías
- Laboratorio de Investigaciones Microbiológicas de Lagunas Andinas (LIMLA), Planta Piloto de Procesos Industriales Microbiológicos (PROIMI), CCT, CONICET, San Miguel de Tucumán, Tucumán, Argentina
| | - Ramon Rosselló-Móra
- Marine Microbiology Group, Department of Ecology and Marine Resources, Institut Mediterrani d'Estudis Avançats, IMEDEA (CSIC-UIB), 07190 Esporles, Illes Balears, Spain
| | - Thorsten Stoeck
- Department of Ecology, University of Kaiserslautern, 67663, Kaiserslautern, Germany
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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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19
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Xu D, Li R, Hu C, Sun P, Jiao N, Warren A. Microbial Eukaryote Diversity and Activity in the Water Column of the South China Sea Based on DNA and RNA High Throughput Sequencing. Front Microbiol 2017; 8:1121. [PMID: 28659910 PMCID: PMC5469884 DOI: 10.3389/fmicb.2017.01121] [Citation(s) in RCA: 43] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2017] [Accepted: 06/01/2017] [Indexed: 12/20/2022] Open
Abstract
To study the diversity and metabolic activity of microbial eukaryotes in the water column of the South China Sea, genomic DNA and RNA were co-extracted from samples collected down to bathyal depth at two sites. V9 regions of both SSU rRNA gene and its transcript (cDNA) were amplified and sequenced using high throughput sequencing. Our study revealed: (1) DNA and RNA datasets showed significant differences in microbial eukaryote community composition, with the variability between the two datasets for the same sample exceeding that between samples within each dataset, indicating that nucleic acid source overrode environmental factors in determining the composition of microeukaryotes; (2) despite the differences in community composition between the two datasets, both DNA and RNA revealed similar depth-related distribution patterns of microbial eukaryotes; (3) using the ratio of RNA: DNA as a proxy of relative metabolic activity, a depth-related pattern was found for the relative metabolic activity of some but not all groups of microbial eukaryotes, with the highest activity for the groups with depth-related pattern usually found in the middle water layers; and (4) the presence of live and active photoautotrophic microbial eukaryotes in the deep ocean was confirmed, indicating that they play an important role in controlling the deep-sea organic carbon pool. Overall, our study sheds light on the diversity and activity of microbial eukaryotes in the water column of a tropical oligotrophic ocean and their potential contributions in the downward transportation of organic material from the surface ocean to the deep via the biological pump.
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Affiliation(s)
- Dapeng Xu
- State Key Laboratory of Marine Environmental Science, Institute of Marine Microbes and Ecospheres, Xiamen UniversityXiamen, China
| | - Ran Li
- State Key Laboratory of Marine Environmental Science, Institute of Marine Microbes and Ecospheres, Xiamen UniversityXiamen, China
| | - Chen Hu
- State Key Laboratory of Marine Environmental Science, Institute of Marine Microbes and Ecospheres, Xiamen UniversityXiamen, China
| | - Ping Sun
- Key Laboratory of the Ministry of Education for Coastal and Wetland Ecosystem, College of the Environment and Ecology, Xiamen UniversityXiamen, China
| | - Nianzhi Jiao
- State Key Laboratory of Marine Environmental Science, Institute of Marine Microbes and Ecospheres, Xiamen UniversityXiamen, China
| | - Alan Warren
- Department of Life Sciences, Natural History MuseumLondon, United Kingdom
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20
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Bojko J, Bącela-Spychalska K, Stebbing PD, Dunn AM, Grabowski M, Rachalewski M, Stentiford GD. Parasites, pathogens and commensals in the "low-impact" non-native amphipod host Gammarus roeselii. Parasit Vectors 2017; 10:193. [PMID: 28427445 PMCID: PMC5397875 DOI: 10.1186/s13071-017-2108-6] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2017] [Accepted: 03/24/2017] [Indexed: 12/02/2022] Open
Abstract
Background Whilst vastly understudied, pathogens of non-native species (NNS) are increasingly recognised as important threats to native wildlife. This study builds upon recent recommendations for improved screening for pathogens in NNS by focusing on populations of Gammarus roeselii in Chojna, north-western Poland. At this location, and in other parts of continental Europe, G. roeselii is considered a well-established and relatively ‘low-impact’ invader, with little understanding about its underlying pathogen profile and even less on potential spill-over of these pathogens to native species. Results Using a combination of histological, ultrastructural and phylogenetic approaches, we define a pathogen profile for non-native populations of G. roeselii in Poland. This profile comprised acanthocephalans (Polymorphus minutus Goese, 1782 and Pomphorhynchus sp.), digenean trematodes, commensal rotifers, commensal and parasitic ciliated protists, gregarines, microsporidia, a putative rickettsia-like organism, filamentous bacteria and two viral pathogens, the majority of which are previously unknown to science. To demonstrate potential for such pathogenic risks to be characterised from a taxonomic perspective, one of the pathogens, a novel microsporidian, is described based upon its pathology, developmental cycle and SSU rRNA gene phylogeny. The novel microsporidian Cucumispora roeselii n. sp. displayed closest morphological and phylogenetic similarity to two previously described taxa, Cucumispora dikerogammari (Ovcharenko & Kurandina, 1987), and Cucumispora ornata Bojko, Dunn, Stebbing, Ross, Kerr & Stentiford, 2015. Conclusions In addition to our discovery extending the host range for the genus Cucumispora Ovcharenko, Bacela, Wilkinson, Ironside, Rigaud & Wattier, 2010 outside of the amphipod host genus Dikerogammarus Stebbing, we reveal significant potential for the co-transfer of (previously unknown) pathogens alongside this host when invading novel locations. This study highlights the importance of pre-invasion screening of low-impact NNS and, provides a means to document and potentially mitigate the additional risks posed by previously unknown pathogens. Electronic supplementary material The online version of this article (doi:10.1186/s13071-017-2108-6) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Jamie Bojko
- Faculty of Biological Sciences, University of Leeds, Leeds, LS2 9JT, UK.,Pathology and Molecular Systematics Team, Centre for Environment, Fisheries and Aquaculture Science (Cefas), Weymouth Laboratory, Weymouth, Dorset, DT4 8UB, UK
| | - Karolina Bącela-Spychalska
- Department of Invertebrate Zoology & Hydrobiology, University of Lodz, Banacha 12/16, 90-237, Lodz, Poland
| | - Paul D Stebbing
- Epidemiology and Risk Team, Centre for Environment, Fisheries and Aquaculture Science (Cefas), Weymouth Laboratory, Weymouth, Dorset, DT4 8UB, UK
| | - Alison M Dunn
- Faculty of Biological Sciences, University of Leeds, Leeds, LS2 9JT, UK
| | - Michał Grabowski
- Department of Invertebrate Zoology & Hydrobiology, University of Lodz, Banacha 12/16, 90-237, Lodz, Poland
| | - Michał Rachalewski
- Department of Invertebrate Zoology & Hydrobiology, University of Lodz, Banacha 12/16, 90-237, Lodz, Poland
| | - Grant D Stentiford
- Pathology and Molecular Systematics Team, Centre for Environment, Fisheries and Aquaculture Science (Cefas), Weymouth Laboratory, Weymouth, Dorset, DT4 8UB, UK. .,European Union Reference Laboratory for Crustacean Diseases, Centre for Environment, Fisheries and Aquaculture Science (Cefas), Weymouth Laboratory, Weymouth, Dorset, DT4 8UB, UK.
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21
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Xu D, Jiao N, Ren R, Warren A. Distribution and Diversity of Microbial Eukaryotes in Bathypelagic Waters of the South China Sea. J Eukaryot Microbiol 2016; 64:370-382. [PMID: 27687286 DOI: 10.1111/jeu.12372] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2016] [Revised: 09/13/2016] [Accepted: 09/22/2016] [Indexed: 11/28/2022]
Abstract
Little is known about the biodiversity of microbial eukaryotes in the South China Sea, especially in waters at bathyal depths. Here, we employed SSU rDNA gene sequencing to reveal the diversity and community structure across depth and distance gradients in the South China Sea. Vertically, the highest alpha diversity was found at 75-m depth. The communities of microbial eukaryotes were clustered into shallow-, middle-, and deep-water groups according to the depth from which they were collected, indicating a depth-related diversity and distribution pattern. Rhizaria sequences dominated the microeukaryote community and occurred in all samples except those from less than 50-m deep, being most abundant near the sea floor where they contributed ca. 64-97% and 40-74% of the total sequences and OTUs recovered, respectively. A large portion of rhizarian OTUs has neither a nearest named neighbor nor a nearest neighbor in the GenBank database which indicated the presence of new phylotypes in the South China Sea. Given their overwhelming abundance and richness, further phylogenetic analysis of rhizarians were performed and three new genetic clusters were revealed containing sequences retrieved from the deep waters of the South China Sea. Our results shed light on the diversity and community structure of microbial eukaryotes in this not yet fully explored area.
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Affiliation(s)
- Dapeng Xu
- State Key Laboratory of Marine Environmental Science, Xiamen University, Xiamen, 361102, China.,Institute of Marine Microbes and Ecospheres, Xiamen University, Xiamen, 361102, China
| | - Nianzhi Jiao
- State Key Laboratory of Marine Environmental Science, Xiamen University, Xiamen, 361102, China.,Institute of Marine Microbes and Ecospheres, Xiamen University, Xiamen, 361102, China
| | - Rui Ren
- State Key Laboratory of Marine Environmental Science, Xiamen University, Xiamen, 361102, China.,Institute of Marine Microbes and Ecospheres, Xiamen University, Xiamen, 361102, China
| | - Alan Warren
- Department of Life Sciences, Natural History Museum, London, SW7 5BD, United Kingdom
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22
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Piredda R, Tomasino MP, D'Erchia AM, Manzari C, Pesole G, Montresor M, Kooistra WHCF, Sarno D, Zingone A. Diversity and temporal patterns of planktonic protist assemblages at a Mediterranean Long Term Ecological Research site. FEMS Microbiol Ecol 2016; 93:fiw200. [DOI: 10.1093/femsec/fiw200] [Citation(s) in RCA: 105] [Impact Index Per Article: 13.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/25/2016] [Indexed: 11/13/2022] Open
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23
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Rocke E, Jing H, Xia X, Liu H. Effects of Hypoxia on the Phylogenetic Composition and Species Distribution of Protists in a Subtropical Harbor. MICROBIAL ECOLOGY 2016; 72:96-105. [PMID: 26979838 DOI: 10.1007/s00248-016-0751-7] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/06/2015] [Accepted: 03/02/2016] [Indexed: 06/05/2023]
Abstract
Tolo Harbor, a subtropical semi-enclosed coastal water body, is surrounded by an expanding urban community, which contributes to large concentrations of nutrient runoff, leading to algal blooms and localized hypoxic episodes. Present knowledge of protist distributions in subtropical waters during hypoxic conditions is very limited. In this study, therefore, we combined parallel 454 pyrosequencing technology and denaturing gradient gel electrophoresis (DGGE) fingerprint analyses to reveal the protist community shifts before, during, and after a 2-week hypoxic episode during the summer of 2011. Hierarchical clustering for DGGE demonstrated similar grouping of hypoxic samples separately from oxic samples. Dissolved oxygen (DO) concentration and dissolved inorganic nitrogen:phosphate (DIN:PO4) concentrations significantly affected OTU distribution in 454 sequenced samples, and a shift toward a ciliate and marine alveolate clade II (MALV II) species composition occurred as waters shifted from oxic to hypoxic. These results suggest that protist community shifts toward heterotrophic and parasitic tendencies as well as decreased diversity and richness in response to hypoxic outbreaks.
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Affiliation(s)
- Emma Rocke
- Division of Life Science, Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong
| | - Hongmei Jing
- Division of Life Science, Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong
- Sanya Institute of Deep-Sea Science and Engineering, Chinese Academy of Sciences, Sanya, 572000, China
| | - Xiaomin Xia
- Division of Life Science, Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong
| | - Hongbin Liu
- Division of Life Science, Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong.
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24
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Yuasa T, Takahashi O. Light and electron microscopic observations of the reproductive swarmer cells of nassellarian and spumellarian polycystines (Radiolaria). Eur J Protistol 2016; 54:19-32. [PMID: 27023270 DOI: 10.1016/j.ejop.2016.02.007] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2016] [Revised: 02/24/2016] [Accepted: 02/25/2016] [Indexed: 10/22/2022]
Abstract
We observed reproductive swarmer cells of the nassellarian and spumellarian polycystine radiolarians Didymocyrtis ceratospyris, Pterocanium praetextum, Tetrapyle sp., and Triastrum aurivillii using light, scanning and transmission electron microscopy. The swarmer cells had subspherical to ovoid or spindle shapes with two unequal flagella tapered to whip-like ends. The cell size was approximately 2.5-5.5μm long and 1.6-2.2μm wide, which is significantly smaller than that of the collodarian (colonial or naked) polycystine radiolarians. Transmission electron microscopy revealed that the swarmer cells possessed a nucleus, mitochondria with tubular cristae, Golgi body, and small lipid droplets in the cytoplasm; they also had a large vacuole in which a single crystalline inclusion (approx. 1.0-1.5μm) that was probably celestite (SrSO4) was enclosed. The swarmer cells were released directly from the parent cells. At that time, morphological change such as encystment was not observed in the parent cells, and the axopodia remained extended in a period of swarmer reproduction for floating existence. This may have prevented the polycystine swarmers from rapidly sinking down to great depths. Thus, we concluded that the polycystine radiolarians release the swarmer cells into the photic layer in the same way as the symbiotic acantharians.
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Affiliation(s)
- Tomoko Yuasa
- Department of Astronomy and Earth Sciences, Tokyo Gakugei University, Koganei, Tokyo 184-8501, Japan.
| | - Osamu Takahashi
- Department of Astronomy and Earth Sciences, Tokyo Gakugei University, Koganei, Tokyo 184-8501, Japan
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Pasulka AL, Levin LA, Steele JA, Case DH, Landry MR, Orphan VJ. Microbial eukaryotic distributions and diversity patterns in a deep-sea methane seep ecosystem. Environ Microbiol 2016; 18:3022-43. [PMID: 26663587 DOI: 10.1111/1462-2920.13185] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2015] [Revised: 12/03/2015] [Accepted: 12/08/2015] [Indexed: 11/30/2022]
Abstract
Although chemosynthetic ecosystems are known to support diverse assemblages of microorganisms, the ecological and environmental factors that structure microbial eukaryotes (heterotrophic protists and fungi) are poorly characterized. In this study, we examined the geographic, geochemical and ecological factors that influence microbial eukaryotic composition and distribution patterns within Hydrate Ridge, a methane seep ecosystem off the coast of Oregon using a combination of high-throughput 18S rRNA tag sequencing, terminal restriction fragment length polymorphism fingerprinting, and cloning and sequencing of full-length 18S rRNA genes. Microbial eukaryotic composition and diversity varied as a function of substrate (carbonate versus sediment), activity (low activity versus active seep sites), sulfide concentration, and region (North versus South Hydrate Ridge). Sulfide concentration was correlated with changes in microbial eukaryotic composition and richness. This work also revealed the influence of oxygen content in the overlying water column and water depth on microbial eukaryotic composition and diversity, and identified distinct patterns from those previously observed for bacteria, archaea and macrofauna in methane seep ecosystems. Characterizing the structure of microbial eukaryotic communities in response to environmental variability is a key step towards understanding if and how microbial eukaryotes influence seep ecosystem structure and function.
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Affiliation(s)
- Alexis L Pasulka
- Integrative Oceanography Division and Center for Marine Biodiversity and Conservation, Scripps Institution of Oceanography, University of California, San Diego, CA, USA. .,Division of Geological and Planetary Sciences, California Institute of Technology, Pasadena, CA, USA.
| | - Lisa A Levin
- Integrative Oceanography Division and Center for Marine Biodiversity and Conservation, Scripps Institution of Oceanography, University of California, San Diego, CA, USA
| | - Josh A Steele
- Division of Geological and Planetary Sciences, California Institute of Technology, Pasadena, CA, USA.,Southern California Coastal Water Research Project, Costa Mesa, CA, USA
| | - David H Case
- Division of Geological and Planetary Sciences, California Institute of Technology, Pasadena, CA, USA
| | - Michael R Landry
- Integrative Oceanography Division and Center for Marine Biodiversity and Conservation, Scripps Institution of Oceanography, University of California, San Diego, CA, USA
| | - Victoria J Orphan
- Division of Geological and Planetary Sciences, California Institute of Technology, Pasadena, CA, USA
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26
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Pánek T, Táborský P, Pachiadaki MG, Hroudová M, Vlček Č, Edgcomb VP, Čepička I. Combined Culture-Based and Culture-Independent Approaches Provide Insights into Diversity of Jakobids, an Extremely Plesiomorphic Eukaryotic Lineage. Front Microbiol 2015; 6:1288. [PMID: 26635756 PMCID: PMC4649034 DOI: 10.3389/fmicb.2015.01288] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2015] [Accepted: 11/03/2015] [Indexed: 11/13/2022] Open
Abstract
We used culture-based and culture-independent approaches to discover diversity and ecology of anaerobic jakobids (Excavata: Jakobida), an overlooked, deep-branching lineage of free-living nanoflagellates related to Euglenozoa. Jakobids are among a few lineages of nanoflagellates frequently detected in anoxic habitats by PCR-based studies, however only two strains of a single jakobid species have been isolated from those habitats. We recovered 712 environmental sequences and cultured 21 new isolates of anaerobic jakobids that collectively represent at least ten different species in total, from which four are uncultured. Two cultured species have never been detected by environmental, PCR-based methods. Surprisingly, culture-based and culture-independent approaches were able to reveal a relatively high proportion of overall species diversity of anaerobic jakobids—60 or 80%, respectively. Our phylogenetic analyses based on SSU rDNA and six protein-coding genes showed that anaerobic jakobids constitute a clade of morphologically similar, but genetically and ecologically diverse protists—Stygiellidae fam. nov. Our investigation combines culture-based and environmental molecular-based approaches to capture a wider extent of species diversity and shows Stygiellidae as a group that ordinarily inhabits anoxic, sulfide- and ammonium-rich marine habitats worldwide.
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Affiliation(s)
- Tomáš Pánek
- Department of Zoology, Faculty of Science, Charles University in Prague Prague, Czech Republic
| | - Petr Táborský
- Department of Zoology, Faculty of Science, Charles University in Prague Prague, Czech Republic
| | - Maria G Pachiadaki
- Geology and Geophysics Department, Woods Hole Oceanographic Institution Woods Hole, MA, USA
| | - Miluše Hroudová
- Department of Genomics and Bioinformatics, Institute of Molecular Genetics, Czech Academy of Sciences Prague, Czech Republic
| | - Čestmír Vlček
- Department of Genomics and Bioinformatics, Institute of Molecular Genetics, Czech Academy of Sciences Prague, Czech Republic
| | - Virginia P Edgcomb
- Geology and Geophysics Department, Woods Hole Oceanographic Institution Woods Hole, MA, USA
| | - Ivan Čepička
- Department of Zoology, Faculty of Science, Charles University in Prague Prague, Czech Republic
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Tanabe AS, Nagai S, Hida K, Yasuike M, Fujiwara A, Nakamura Y, Takano Y, Katakura S. Comparative study of the validity of three regions of the 18S-rRNA gene for massively parallel sequencing-based monitoring of the planktonic eukaryote community. Mol Ecol Resour 2015; 16:402-14. [PMID: 26309223 DOI: 10.1111/1755-0998.12459] [Citation(s) in RCA: 49] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2014] [Revised: 08/05/2015] [Accepted: 08/21/2015] [Indexed: 11/27/2022]
Abstract
The nuclear 18S-rRNA gene has been used as a metabarcoding marker in massively parallel sequencing (MPS)-based environmental surveys for plankton biodiversity research. However, different hypervariable regions have been used in different studies, and their utility has been debated among researchers. In this study, detailed investigations into 18S-rRNA were carried out; we investigated the effective number of sequences deposited in international nucleotide sequence databases (INSDs), the amplification bias, and the amplicon sequence variability among the three variable regions, V1-3, V4-5 and V7-9, using in silico polymerase chain reaction (PCR) amplification based on INSDs. We also examined the primer universality and the taxonomic identification power, using MPS-based environmental surveys in the Sea of Okhotsk, to determine which region is more useful for MPS-based monitoring. The primer universality was not significantly different among the three regions, but the number of sequences deposited in INSDs was markedly larger for the V4-5 region than for the other two regions. The sequence variability was significantly different, with the highest variability in the V1-3 region, followed by the V7-9 region, and the lowest variability in the V4-5 region. The results of the MPS-based environmental surveys showed significantly higher identification power in the V1-3 and V7-9 regions than in the V4-5 region, but no significant difference was detected between the V1-3 and V7-9 regions. We therefore conclude that the V1-3 region will be the most suitable for future MPS-based monitoring of natural eukaryote communities, as the number of sequences deposited in INSDs increases.
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Affiliation(s)
- Akifumi S Tanabe
- Research Center for Aquatic Genomics, National Research Institute of Fisheries Science, 2-12-4 Fukuura, Kanazawa-ku, Yokohama, Kanagawa, 236-8648, Japan
| | - Satoshi Nagai
- Research Center for Aquatic Genomics, National Research Institute of Fisheries Science, 2-12-4 Fukuura, Kanazawa-ku, Yokohama, Kanagawa, 236-8648, Japan
| | - Kohsuke Hida
- AXIOHELIX Co. Ltd., 5-11 Kakozaki, Nihonbashi, Chuouku, Tokyo, 103-0015, Japan
| | - Motoshige Yasuike
- Research Center for Aquatic Genomics, National Research Institute of Fisheries Science, 2-12-4 Fukuura, Kanazawa-ku, Yokohama, Kanagawa, 236-8648, Japan
| | - Atushi Fujiwara
- Research Center for Aquatic Genomics, National Research Institute of Fisheries Science, 2-12-4 Fukuura, Kanazawa-ku, Yokohama, Kanagawa, 236-8648, Japan
| | - Yoji Nakamura
- Research Center for Aquatic Genomics, National Research Institute of Fisheries Science, 2-12-4 Fukuura, Kanazawa-ku, Yokohama, Kanagawa, 236-8648, Japan
| | - Yoshihito Takano
- Research Center for Aquatic Genomics, National Research Institute of Fisheries Science, 2-12-4 Fukuura, Kanazawa-ku, Yokohama, Kanagawa, 236-8648, Japan
| | - Seiji Katakura
- City of Mombetsu, Kaiyo-koryukan, Kaiyo-koen, Mombetsu, Hokkaido, 094-0031, Japan
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28
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Rodriguez-Mora MJ, Scranton MI, Taylor GT, Chistoserdov AY. The dynamics of the bacterial diversity in the redox transition and anoxic zones of the Cariaco Basin assessed by parallel tag sequencing. FEMS Microbiol Ecol 2015. [PMID: 26209697 DOI: 10.1093/femsec/fiv088] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023] Open
Abstract
Massively parallel tag sequencing was applied to describe the bacterial diversity in the redox transition and anoxic zones of the Cariaco Basin. In total, 14 samples from the Cariaco Basin were collected over a period of eight years from two stations. A total of 244 357 unique bacterial V6 amplicons were sequenced. The total number of operational taxonomic units (OTUs) found in this study was 4692, with a range of 511-1491 OTUs per sample. Approximately 95% of the OTUs found in the redox transition zone and anoxic layers of Cariaco are represented by less than 50 amplicons suggesting that only about 5% of the bacterial OTUs are responsible for the bulk of the microbial processes in the basin redox transition and anoxic zones. The same dominant OTUs were observed across all eight years of sampling although periodic fluctuations in their proportion were apparent. No distinctive differences were observed between the bacterial communities from the redox transition and anoxic layers of the Cariaco Basin water column. The largest proportion of amplicons belongs to Gammaproteobacteria represented mostly by sulfide oxidizers, followed by Marine Group A (originally described as SAR406; Gordon and Giovannoni 1996), a group of uncultured bacteria hypothesized to be involved in metal reduction, and sulfate-reducing Deltaproteobacteria. Gammaproteobacteria, Deltaproteobacteria and Marine Group A make up 67-90% of all V6 amplicons sequenced in this study. This strongly suggests that the basin's microbial communities are actively involved in the sulfur-related metabolism and coupling of the sulfur and carbon cycles. According to detrended canonical correspondence analysis, ecological factors such as chemoautotrophy, nitrate and oxidized and reduced sulfur compounds influence the structuring and distribution of the Cariaco microbial communities.
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Affiliation(s)
| | - Mary I Scranton
- School of Marine and Atmospheric Sciences, Stony Brook University, Stony Brook, NY 11794, USA
| | - Gordon T Taylor
- School of Marine and Atmospheric Sciences, Stony Brook University, Stony Brook, NY 11794, USA
| | - Andrei Y Chistoserdov
- Department of Biology, University of Louisiana at Lafayette, Lafayette, LA 70504, USA
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Duret MT, Pachiadaki MG, Stewart FJ, Sarode N, Christaki U, Monchy S, Srivastava A, Edgcomb VP. Size-fractionated diversity of eukaryotic microbial communities in the Eastern Tropical North Pacific oxygen minimum zone. FEMS Microbiol Ecol 2015; 91:fiv037. [DOI: 10.1093/femsec/fiv037] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/29/2015] [Indexed: 11/14/2022] Open
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Forster D, Bittner L, Karkar S, Dunthorn M, Romac S, Audic S, Lopez P, Stoeck T, Bapteste E. Testing ecological theories with sequence similarity networks: marine ciliates exhibit similar geographic dispersal patterns as multicellular organisms. BMC Biol 2015; 13:16. [PMID: 25762112 PMCID: PMC4381497 DOI: 10.1186/s12915-015-0125-5] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2014] [Accepted: 01/28/2015] [Indexed: 11/24/2022] Open
Abstract
BACKGROUND High-throughput sequencing technologies are lifting major limitations to molecular-based ecological studies of eukaryotic microbial diversity, but analyses of the resulting millions of short sequences remain a major bottleneck for these approaches. Here, we introduce the analytical and statistical framework of sequence similarity networks, increasingly used in evolutionary studies and graph theory, into the field of ecology to analyze novel pyrosequenced V4 small subunit rDNA (SSU-rDNA) sequence data sets in the context of previous studies, including SSU-rDNA Sanger sequence data from cultured ciliates and from previous environmental diversity inventories. RESULTS Our broadly applicable protocol quantified the progress in the description of genetic diversity of ciliates by environmental SSU-rDNA surveys, detected a fundamental historical bias in the tendency to recover already known groups in these surveys, and revealed substantial amounts of hidden microbial diversity. Moreover, network measures demonstrated that ciliates are not globally dispersed, but are structured by habitat and geographical location at intermediate geographical scale, as observed for bacteria, plants, and animals. CONCLUSIONS Currently available 'universal' primers used for local in-depth sequencing surveys provide little hope to exhaust the significantly higher ciliate (and most likely microbial) diversity than previously thought. Network analyses such as presented in this study offer a promising way to guide the design of novel primers and to further explore this vast and structured microbial diversity.
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Affiliation(s)
- Dominik Forster
- Department of Ecology, University of Kaiserslautern, Erwin-Schrödinger-Straße 14, Kaiserslautern, D-67633, Germany.
| | - Lucie Bittner
- Department of Ecology, University of Kaiserslautern, Erwin-Schrödinger-Straße 14, Kaiserslautern, D-67633, Germany.
- CNRS, FR3631, Institut de Biologie Paris-Seine, Paris, F-75005, France.
- Sorbonne Universités, UPMC Univ Paris 06, Institut de Biologie Paris-Seine (IBPS), Paris, F-75005, France.
| | - Slim Karkar
- Sorbonne Universités, UPMC Univ Paris 06, Institut de Biologie Paris-Seine (IBPS), Paris, F-75005, France.
- CNRS, UMR7138, Institut de Biologie Paris-Seine, Paris, F-75005, France.
| | - Micah Dunthorn
- Department of Ecology, University of Kaiserslautern, Erwin-Schrödinger-Straße 14, Kaiserslautern, D-67633, Germany.
| | - Sarah Romac
- CNRS, UMR 7144, Station Biologique de Roscoff, Place Georges Teissier, Roscoff, F-29680, France.
- Sorbonne Universités, UPMC Univ Paris 06, UMR 7144, Station Biologique de Roscoff, Place Georges Teissier, Roscoff, F-29680, France.
| | - Stéphane Audic
- CNRS, UMR 7144, Station Biologique de Roscoff, Place Georges Teissier, Roscoff, F-29680, France.
- Sorbonne Universités, UPMC Univ Paris 06, UMR 7144, Station Biologique de Roscoff, Place Georges Teissier, Roscoff, F-29680, France.
| | - Philippe Lopez
- Sorbonne Universités, UPMC Univ Paris 06, Institut de Biologie Paris-Seine (IBPS), Paris, F-75005, France.
- CNRS, UMR7138, Institut de Biologie Paris-Seine, Paris, F-75005, France.
| | - Thorsten Stoeck
- Department of Ecology, University of Kaiserslautern, Erwin-Schrödinger-Straße 14, Kaiserslautern, D-67633, Germany.
| | - Eric Bapteste
- Sorbonne Universités, UPMC Univ Paris 06, Institut de Biologie Paris-Seine (IBPS), Paris, F-75005, France.
- CNRS, UMR7138, Institut de Biologie Paris-Seine, Paris, F-75005, France.
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31
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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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32
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Oikonomou A, Filker S, Breiner HW, Stoeck T. Protistan diversity in a permanently stratified meromictic lake (Lake Alatsee, SW Germany). Environ Microbiol 2014; 17:2144-57. [PMID: 25330396 DOI: 10.1111/1462-2920.12666] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2014] [Revised: 09/26/2014] [Accepted: 10/08/2014] [Indexed: 11/28/2022]
Abstract
Protists play a crucial role for ecosystem function(ing) and oxygen is one of the strongest barriers against their local dispersal. However, protistan diversity in freshwater habitats with oxygen gradients received very little attention. We applied high-throughput sequencing of the V9 region (18S rRNA gene) to provide a hitherto unique spatiotemporal analysis of protistan diversity along the oxygen gradient of a freshwater meromictic lake (Lake Alatsee, SW Germany). In the mixolimnion, the communities experienced most seasonal structural changes, with Stramenopiles dominating in autumn and Dinoflagellata in summer. The suboxic interface supported the highest diversity, but only 23 OTUs95% (mainly Euglenozoa, after quality check and removal of operational taxonomic units (OTUs) with less than three sequences) were exclusively associated with this habitat. Eukaryotic communities in the anoxic monimolimnion showed the most stable seasonal pattern, with Chrysophyta and Bicosoecida being the dominant taxa. Our data pinpoint to the ecological role of the interface as a short-term 'meeting point' for protists, contributing to the coupling of the mixolimnion and the monimolimnion. Our analyses of divergent genetic diversity suggest a high degree of previously undescribed OTUs. Future research will have to reveal if this result actually points to a high number of undescribed species in such freshwater habitats.
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Affiliation(s)
- Andreas Oikonomou
- Department of Ecology, University of Kaiserslautern, Erwin Schroedinger Str. 14, D-67663, Kaiserslautern, Germany
| | - Sabine Filker
- Department of Ecology, University of Kaiserslautern, Erwin Schroedinger Str. 14, D-67663, Kaiserslautern, Germany
| | - Hans-Werner Breiner
- Department of Ecology, University of Kaiserslautern, Erwin Schroedinger Str. 14, D-67663, Kaiserslautern, Germany
| | - Thorsten Stoeck
- Department of Ecology, University of Kaiserslautern, Erwin Schroedinger Str. 14, D-67663, Kaiserslautern, Germany
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33
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The influence of vent systems on pelagic eukaryotic micro-organism composition in the Nordic Seas. Polar Biol 2014. [DOI: 10.1007/s00300-014-1621-8] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
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34
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Parris DJ, Ganesh S, Edgcomb VP, DeLong EF, Stewart FJ. Microbial eukaryote diversity in the marine oxygen minimum zone off northern Chile. Front Microbiol 2014; 5:543. [PMID: 25389417 PMCID: PMC4211540 DOI: 10.3389/fmicb.2014.00543] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2014] [Accepted: 09/29/2014] [Indexed: 02/02/2023] Open
Abstract
Molecular surveys are revealing diverse eukaryotic assemblages in oxygen-limited ocean waters. These communities may play pivotal ecological roles through autotrophy, feeding, and a wide range of symbiotic associations with prokaryotes. We used 18S rRNA gene sequencing to provide the first snapshot of pelagic microeukaryotic community structure in two cellular size fractions (0.2–1.6 μm, >1.6 μm) from seven depths through the anoxic oxygen minimum zone (OMZ) off northern Chile. Sequencing of >154,000 amplicons revealed contrasting patterns of phylogenetic diversity across size fractions and depths. Protist and total eukaryote diversity in the >1.6 μm fraction peaked at the chlorophyll maximum in the upper photic zone before declining by ~50% in the OMZ. In contrast, diversity in the 0.2–1.6 μm fraction, though also elevated in the upper photic zone, increased four-fold from the lower oxycline to a maximum at the anoxic OMZ core. Dinoflagellates of the Dinophyceae and endosymbiotic Syndiniales clades dominated the protist assemblage at all depths (~40–70% of sequences). Other protist groups varied with depth, with the anoxic zone community of the larger size fraction enriched in euglenozoan flagellates and acantharean radiolarians (up to 18 and 40% of all sequences, respectively). The OMZ 0.2–1.6 μm fraction was dominated (11–99%) by Syndiniales, which exhibited depth-specific variation in composition and total richness despite uniform oxygen conditions. Metazoan sequences, though confined primarily to the 1.6 μm fraction above the OMZ, were also detected within the anoxic zone where groups such as copepods increased in abundance relative to the oxycline and upper OMZ. These data, compared to those from other low-oxygen sites, reveal variation in OMZ microeukaryote composition, helping to identify clades with potential adaptations to oxygen-depletion.
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Affiliation(s)
- Darren J Parris
- School of Biology, Georgia Institute of Technology Atlanta, GA, USA
| | - Sangita Ganesh
- School of Biology, Georgia Institute of Technology Atlanta, GA, USA
| | | | - Edward F DeLong
- Department of Civil and Environmental Engineering, Massachusetts Institute of Technology, Parsons Laboratory 48 Cambridge, UK ; Center for Microbial Ecology, Research and Education Hawaii, HI, USA
| | - Frank J Stewart
- School of Biology, Georgia Institute of Technology Atlanta, GA, USA
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35
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Intracellular diversity of the V4 and V9 regions of the 18S rRNA in marine protists (radiolarians) assessed by high-throughput sequencing. PLoS One 2014; 9:e104297. [PMID: 25090095 PMCID: PMC4121268 DOI: 10.1371/journal.pone.0104297] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2013] [Accepted: 07/12/2014] [Indexed: 11/25/2022] Open
Abstract
Metabarcoding is a powerful tool for exploring microbial diversity in the environment, but its accurate interpretation is impeded by diverse technical (e.g. PCR and sequencing errors) and biological biases (e.g. intra-individual polymorphism) that remain poorly understood. To help interpret environmental metabarcoding datasets, we investigated the intracellular diversity of the V4 and V9 regions of the 18S rRNA gene from Acantharia and Nassellaria (radiolarians) using 454 pyrosequencing. Individual cells of radiolarians were isolated, and PCRs were performed with generalist primers to amplify the V4 and V9 regions. Different denoising procedures were employed to filter the pyrosequenced raw amplicons (Acacia, AmpliconNoise, Linkage method). For each of the six isolated cells, an average of 541 V4 and 562 V9 amplicons assigned to radiolarians were obtained, from which one numerically dominant sequence and several minor variants were found. At the 97% identity, a diversity metrics commonly used in environmental surveys, up to 5 distinct OTUs were detected in a single cell. However, most amplicons grouped within a single OTU whereas other OTUs contained very few amplicons. Different analytical methods provided evidence that most minor variants forming different OTUs correspond to PCR and sequencing artifacts. Duplicate PCR and sequencing from the same DNA extract of a single cell had only 9 to 16% of unique amplicons in common, and alignment visualization of V4 and V9 amplicons showed that most minor variants contained substitutions in highly-conserved regions. We conclude that intracellular variability of the 18S rRNA in radiolarians is very limited despite its multi-copy nature and the existence of multiple nuclei in these protists. Our study recommends some technical guidelines to conservatively discard artificial amplicons from metabarcoding datasets, and thus properly assess the diversity and richness of protists in the environment.
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36
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Wu W, Huang B, Liao Y, Sun P. Picoeukaryotic diversity and distribution in the subtropical-tropical South China Sea. FEMS Microbiol Ecol 2014; 89:563-79. [PMID: 24849025 DOI: 10.1111/1574-6941.12357] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2014] [Revised: 04/27/2014] [Accepted: 05/16/2014] [Indexed: 11/27/2022] Open
Abstract
Little is known regarding the diversity and distribution of picoeukaryotes in the northwestern Pacific Ocean, although these organisms are vital components of their environment. Here, we used a culture-independent approach to assess the 18S rDNA diversity of picoeukaryotes at six sampling sites along a transcontinental section of the South China Sea. The Alveolata group comprised 58.6% of the clones and was mainly represented by the novel marine alveolates (MALV)-I (18.8%) and MALV-II (30.6%), corresponding to 66.5% of all operational taxonomic units. Sequences affiliated with seven clades of the novel marine stramenopiles (MAST) were widely distributed in different clone libraries. We report an entirely new group representing the deepest evolutionary branch of the Hacrobia; this finding suggests the existence of novel picoeukaryotes at a high taxonomic level. Many phylotypes could not be taxonomically assigned, indicating the presence of numerous previously unknown groups. Horizontally, picoeukaryotic assemblages in the coastal water characterized with the rare occurrence of MALV-I were distinct from offshore communities. Vertically, MAST-4 were mainly retrieved in surface waters; however, the Radiolaria (Rhizaria) were mainly detected in clone libraries from depths of 60 m. Our findings further emphasize the immense diversity of picoeukaryotes, especially in the subtropical-tropical northwestern Pacific Ocean.
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Affiliation(s)
- Wenxue Wu
- Key Laboratory of Coastal and Wetland Ecosystems (Ministry of Education), State Key Laboratory of Marine Environmental Science, Xiamen University, Xiamen, China
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37
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Edgcomb VP, Pachiadaki M. Ciliates along Oxyclines of Permanently Stratified Marine Water Columns. J Eukaryot Microbiol 2014; 61:434-45. [DOI: 10.1111/jeu.12122] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2014] [Revised: 02/28/2014] [Accepted: 02/28/2014] [Indexed: 11/30/2022]
Affiliation(s)
- Virginia P. Edgcomb
- Department of Geology and Geophysics; Woods Hole Oceanographic Institution; Woods Hole Massachusetts 02543
| | - Maria Pachiadaki
- Department of Geology and Geophysics; Woods Hole Oceanographic Institution; Woods Hole Massachusetts 02543
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38
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Dunthorn M, Stoeck T, Clamp J, Warren A, Mahé F. Ciliates and the Rare Biosphere: A Review. J Eukaryot Microbiol 2014; 61:404-9. [DOI: 10.1111/jeu.12121] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2014] [Revised: 03/14/2014] [Accepted: 03/14/2014] [Indexed: 11/27/2022]
Affiliation(s)
- Micah Dunthorn
- Department of Ecology; University of Kaiserslautern; D-67663 Kaiserslautern Germany
| | - Thorsten Stoeck
- Department of Ecology; University of Kaiserslautern; D-67663 Kaiserslautern Germany
| | - John Clamp
- Department of Biology; North Carolina Central University; Durham North Carolina 27707 USA
| | - Alan Warren
- Department of Life Sciences Department; Natural History Museum; London SW7 5BD United Kingdom
| | - Frédéric Mahé
- Department of Ecology; University of Kaiserslautern; D-67663 Kaiserslautern Germany
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39
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Living at the Limits: Evidence for Microbial Eukaryotes Thriving under Pressure in Deep Anoxic, Hypersaline Habitats. ACTA ACUST UNITED AC 2014. [DOI: 10.1155/2014/532687] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
The advent of molecular tools in microbial ecology paved the way to exploit the diversity of microbes in extreme environments. Here, we review these tools as applied in one of the most polyextreme habitats known on our planet, namely, deep hypersaline anoxic basins (DHABs), located at ca. 3000–3500 m depth in the Eastern Mediterranean Sea. Molecular gene signatures amplified from environmental DHAB samples identified a high degree of genetic novelty, as well as distinct communities in the DHABs. Canonical correspondence analyses provided strong evidence that salinity, ion composition, and anoxia were the strongest selection factors shaping protistan community structures, largely preventing cross-colonization among the individual basins. Thus, each investigated basin represents a unique habitat (“isolated islands of evolution”), making DHABs ideal model sites to test evolutionary hypotheses. Fluorescence in situ hybridization assays using specifically designed probes revealed that the obtained genetic signatures indeed originated from indigenous polyextremophiles. Electron microscopy imaging revealed unknown ciliates densely covered with prokaryote ectosymbionts, which may enable adaptations of eukaryotes to DHAB conditions. The research reviewed here significantly advanced our knowledge on polyextremophile eukaryotes, which are excellent models for a number of biological research areas, including ecology, diversity, biotechnology, evolutionary research, physiology, and astrobiology.
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Hugerth LW, Muller EEL, Hu YOO, Lebrun LAM, Roume H, Lundin D, Wilmes P, Andersson AF. Systematic design of 18S rRNA gene primers for determining eukaryotic diversity in microbial consortia. PLoS One 2014; 9:e95567. [PMID: 24755918 PMCID: PMC3995771 DOI: 10.1371/journal.pone.0095567] [Citation(s) in RCA: 135] [Impact Index Per Article: 13.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2013] [Accepted: 03/28/2014] [Indexed: 01/22/2023] Open
Abstract
High-throughput sequencing of ribosomal RNA gene (rDNA) amplicons has opened up the door to large-scale comparative studies of microbial community structures. The short reads currently produced by massively parallel sequencing technologies make the choice of sequencing region crucial for accurate phylogenetic assignments. While for 16S rDNA, relevant regions have been well described, no truly systematic design of 18S rDNA primers aimed at resolving eukaryotic diversity has yet been reported. Here we used 31,862 18S rDNA sequences to design a set of broad-taxonomic range degenerate PCR primers. We simulated the phylogenetic information that each candidate primer pair would retrieve using paired- or single-end reads of various lengths, representing different sequencing technologies. Primer pairs targeting the V4 region performed best, allowing discrimination with paired-end reads as short as 150 bp (with 75% accuracy at genus level). The conditions for PCR amplification were optimised for one of these primer pairs and this was used to amplify 18S rDNA sequences from isolates as well as from a range of environmental samples which were then Illumina sequenced and analysed, revealing good concordance between expected and observed results. In summary, the reported primer sets will allow minimally biased assessment of eukaryotic diversity in different microbial ecosystems.
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Affiliation(s)
- Luisa W. Hugerth
- KTH Royal Institute of Technology, Science for Life Laboratory, School of Biotechnology, Division of Gene Technology, Stockholm, Sweden
| | - Emilie E. L. Muller
- Luxembourg Centre for Systems Biomedicine, University of Luxembourg, Esch-sur-Alzette, Luxembourg
| | - Yue O. O. Hu
- KTH Royal Institute of Technology, Science for Life Laboratory, School of Biotechnology, Division of Gene Technology, Stockholm, Sweden
| | - Laura A. M. Lebrun
- Luxembourg Centre for Systems Biomedicine, University of Luxembourg, Esch-sur-Alzette, Luxembourg
| | - Hugo Roume
- Luxembourg Centre for Systems Biomedicine, University of Luxembourg, Esch-sur-Alzette, Luxembourg
| | - Daniel Lundin
- KTH Royal Institute of Technology, Science for Life Laboratory, School of Biotechnology, Division of Gene Technology, Stockholm, Sweden
| | - Paul Wilmes
- Luxembourg Centre for Systems Biomedicine, University of Luxembourg, Esch-sur-Alzette, Luxembourg
| | - Anders F. Andersson
- KTH Royal Institute of Technology, Science for Life Laboratory, School of Biotechnology, Division of Gene Technology, Stockholm, Sweden
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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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42
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Dunthorn M, Otto J, Berger SA, Stamatakis A, Mahé F, Romac S, de Vargas C, Audic S, Stock A, Kauff F, Stoeck T. Placing environmental next-generation sequencing amplicons from microbial eukaryotes into a phylogenetic context. Mol Biol Evol 2014; 31:993-1009. [PMID: 24473288 DOI: 10.1093/molbev/msu055] [Citation(s) in RCA: 68] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023] Open
Abstract
Nucleotide positions in the hypervariable V4 and V9 regions of the small subunit (SSU)-rDNA locus are normally difficult to align and are usually removed before standard phylogenetic analyses. Yet, with next-generation sequencing data, amplicons of these regions are all that are available to answer ecological and evolutionary questions that rely on phylogenetic inferences. With ciliates, we asked how inclusion of the V4 or V9 regions, regardless of alignment quality, affects tree topologies using distinct phylogenetic methods (including PairDist that is introduced here). Results show that the best approach is to place V4 amplicons into an alignment of full-length Sanger SSU-rDNA sequences and to infer the phylogenetic tree with RAxML. A sliding window algorithm as implemented in RAxML shows, though, that not all nucleotide positions in the V4 region are better than V9 at inferring the ciliate tree. With this approach and an ancestral-state reconstruction, we use V4 amplicons from European nearshore sampling sites to infer that rather than being primarily terrestrial and freshwater, colpodean ciliates may have repeatedly transitioned from terrestrial/freshwater to marine environments.
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Affiliation(s)
- Micah Dunthorn
- Department of Ecology, University of Kaiserslautern, Kaiserslautern, Germany
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Exploring the uncultured microeukaryote majority in the oceans: reevaluation of ribogroups within stramenopiles. ISME JOURNAL 2013; 8:854-66. [PMID: 24196325 DOI: 10.1038/ismej.2013.204] [Citation(s) in RCA: 97] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/02/2013] [Revised: 10/08/2013] [Accepted: 10/09/2013] [Indexed: 11/08/2022]
Abstract
Molecular surveys in planktonic marine systems have unveiled a large novel diversity of small protists. A large part of this diversity belongs to basal heterotrophic stramenopiles and is distributed in a set of polyphyletic ribogroups (described from rDNA sequences) collectively named as MAST (MArine STramenopiles). In the few groups investigated, MAST cells are globally distributed and abundant bacterial grazers, therefore having a putatively large impact on marine ecosystem functioning. The main aim of this study is to reevaluate the MAST ribogroups described so far and to determine whether additional groups can be found. For this purpose, we used traditional and state-of-the-art molecular tools, combining 18S rDNA sequences from publicly available clone libraries, single amplified genomes (SAGs) of planktonic protists, and a pyrosequencing survey from coastal waters and sediments. Our analysis indicated a final set of 18 MAST groups plus 5 new ribogroups within Ochrophyta (named as MOCH). The MAST ribogroups were then analyzed in more detail. Seven were typical of anoxic systems and one of oxic sediments. The rest were clearly members of oxic marine picoplankton. We characterized the genetic diversity within each MAST group and defined subclades for the more diverse (46 subclades in 8 groups). The analyses of sequences within subclades revealed further ecological specializations. Our data provide a renovated framework for phylogenetic classification of the numerous MAST ribogroups and support the notion of a tight link between phylogeny and ecological distribution. These diverse and largely uncultured protists are widespread and ecologically relevant members of marine microbial assemblages.
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44
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Kim DY, Countway PD, Jones AC, Schnetzer A, Yamashita W, Tung C, Caron DA. Monthly to interannual variability of microbial eukaryote assemblages at four depths in the eastern North Pacific. ISME JOURNAL 2013; 8:515-530. [PMID: 24173457 DOI: 10.1038/ismej.2013.173] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/01/2012] [Revised: 08/15/2012] [Accepted: 08/17/2013] [Indexed: 11/09/2022]
Abstract
The monthly, seasonal and interannual variability of microbial eukaryote assemblages were examined at 5 m, the deep chlorophyll maximum, 150 m and 500 m at the San Pedro Ocean Time-series station (eastern North Pacific). The depths spanned transitions in temperature, light, nutrients and oxygen, and included a persistently hypoxic environment at 500 m. Terminal restriction fragment length polymorphism was used for the analysis of 237 samples that were collected between September 2000 and December 2010. Spatiotemporal variability patterns of microeukaryote assemblages indicated the presence of distinct shallow and deep communities at the SPOT station, presumably reflecting taxa that were specifically adapted for the conditions in those environments. Community similarity values between assemblages collected 1 month apart at each depth ranged between ∼20% and ∼84% (averages were ∼50-59%). The assemblage at 5 m was temporally more dynamic than deeper assemblages and also displayed substantial interannual variability during the first ∼3 years of the study. Evidence of seasonality was detected for the microbial eukaryote assemblage at 5 m between January 2008 and December 2010 and at 150 m between September 2000 and December 2003. Seasonality was not detected for assemblages at the deep chlorophyll a maximum, which varied in depth seasonally, or at 500 m. Microbial eukaryote assemblages exhibited cyclical patterns in at least 1 year at each depth, implying an annual resetting of communities. Substantial interannual variability was detected for assemblages at all depths and represented the largest source of temporal variability in this temperate coastal ecosystem.
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Affiliation(s)
- Diane Y Kim
- Department of Biological Sciences, University of Southern California, Los Angeles, CA, USA.
| | - Peter D Countway
- Bigelow Laboratory for Ocean Sciences, East Boothbay, Maine, USA
| | - Adriane C Jones
- Department of Biological Sciences, University of Southern California, Los Angeles, CA, USA
| | - Astrid Schnetzer
- Marine, Earth and Atmospheric Sciences, North Carolina State University, Raleigh, NC, USA
| | - Warren Yamashita
- Department of Biological Sciences, University of Southern California, Los Angeles, CA, USA
| | - Christine Tung
- Department of Biological Sciences, University of Southern California, Los Angeles, CA, USA
| | - David A Caron
- Department of Biological Sciences, University of Southern California, Los Angeles, CA, USA
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45
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Coyne KJ, Countway PD, Pilditch CA, Lee CK, Caron DA, Cary SC. Diversity and Distributional Patterns of Ciliates in Guaymas Basin Hydrothermal Vent Sediments. J Eukaryot Microbiol 2013; 60:433-47. [DOI: 10.1111/jeu.12051] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2012] [Revised: 03/18/2013] [Accepted: 03/18/2013] [Indexed: 11/29/2022]
Affiliation(s)
- Kathryn J. Coyne
- College of Earth, Ocean, and Environment; University of Delaware; 700 Pilottown Road Lewes Delaware 19958 USA
| | - Peter D. Countway
- Department of Biological Sciences; University of Southern California; Los Angeles California 90089-0371 USA
| | - Conrad A. Pilditch
- Department of Biological Sciences; University of Waikato; Private Bag 3105 Hamilton 3240 New Zealand
| | - Charles K. Lee
- Department of Biological Sciences; University of Waikato; Private Bag 3105 Hamilton 3240 New Zealand
| | - David A. Caron
- Department of Biological Sciences; University of Southern California; Los Angeles California 90089-0371 USA
| | - Stephen C. Cary
- College of Earth, Ocean, and Environment; University of Delaware; 700 Pilottown Road Lewes Delaware 19958 USA
- Department of Biological Sciences; University of Waikato; Private Bag 3105 Hamilton 3240 New Zealand
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46
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Berg C, Beckmann S, Jost G, Labrenz M, Jürgens K. Acetate-utilizing bacteria at an oxic-anoxic interface in the Baltic Sea. FEMS Microbiol Ecol 2013; 85:251-61. [PMID: 23521397 DOI: 10.1111/1574-6941.12114] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2012] [Revised: 03/05/2013] [Accepted: 03/14/2013] [Indexed: 11/30/2022] Open
Abstract
Pelagic redoxclines represent chemical gradients of elevated microbial activities. While chemolithoautotrophic microorganisms in these systems are well known as catalysts of major biogeochemical cycles, comparable knowledge on heterotrophic organisms is scarce. Thus, in this study, identity and biogeochemical involvement of active heterotrophs were investigated in stimulation experiments and activity measurements based on samples collected from pelagic redoxclines of the central Baltic Sea in 2005 and 2009. In the 2009 samples, (13)C-acetate 16S rRNA stable isotope probing (16S rRNA-SIP) identified gammaproteobacteria affiliated with Colwellia sp. and Neptunomonas sp. in addition to epsilonproteobacteria related to Arcobacter spp. as active heterotrophs at the oxic-anoxic interface layer. Incubations from sulfidic waters were dominated by two phylogenetic subgroups of Arcobacter. In the 2005 samples, organics, manganese(IV), and iron(III) were added to the sulfidic waters, followed by the determination of metal reduction and identification of the stimulated organisms. Here, the same Arcobacter and Colwellia subgroups were stimulated as in 2009, with Arcobacter predominating in samples, in which manganese(IV) reduction was highest. Our results offer new insights into the heterotrophic bacterial assemblage of Baltic Sea pelagic redoxclines and suggest Arcobacter spp. as a heterotroph with presumed relevance also for manganese cycling.
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Affiliation(s)
- Carlo Berg
- Section Biological Oceanography, Leibniz Institute for Baltic Sea Research Warnemünde, Rostock, Germany
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47
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Rodriguez-Mora MJ, Scranton MI, Taylor GT, Chistoserdov AY. Bacterial community composition in a large marine anoxic basin: a Cariaco Basin time-series survey. FEMS Microbiol Ecol 2013; 84:625-39. [PMID: 23398056 DOI: 10.1111/1574-6941.12094] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2012] [Revised: 01/18/2013] [Accepted: 02/05/2013] [Indexed: 11/30/2022] Open
Abstract
Redox transition zones play a crucial role in biogeochemical cycles of several major elements. Because microorganisms mediate many reactions of these cycles, they actively participate in establishing geochemical gradients. In turn, the geochemical gradients structure microbial communities. We studied the interrelationship between the bacterial community structure and the geochemical gradient in the Cariaco Basin, the largest truly marine anoxic basin. This study's dataset includes bacterial community composition in 113 water column samples as well as the data for environmental variables (gradients of oxygen, hydrogen sulfide, sulfite, thiosulfate, ammonia, nitrate, nitrite, dissolved manganese and iron, dark CO2 fixation, and bacterial abundance) collected between 1997 and 2006. Several prominent bacterial groups are present throughout the entire water column. These include members of Gamma-, Delta-, and Epsilonproteobacteria, as well as members of the Marine Group A, the candidate divisions OP11 and Car731c. Canonical correspondence analysis indicated that microbial communities segregate along vectors representing oxygenated conditions, nitrite, nitrate and anoxic environments represented by chemoautotrophy, ammonia, sulfite, and hydrogen sulfide.
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48
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Anderson R, Wylezich C, Glaubitz S, Labrenz M, Jürgens K. Impact of protist grazing on a key bacterial group for biogeochemical cycling in Baltic Sea pelagic oxic/anoxic interfaces. Environ Microbiol 2013; 15:1580-94. [PMID: 23368413 DOI: 10.1111/1462-2920.12078] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2012] [Revised: 12/17/2012] [Accepted: 12/20/2012] [Indexed: 11/27/2022]
Abstract
Barrier zones between oxic and anoxic water masses (redoxclines) host highly active prokaryotic communities with important roles in biogeochemical cycling. In Baltic Sea pelagic redoxclines, Epsilonproteobacteria of the genus Sulfurimonas (subgroup GD17) have been shown to dominate chemoautotrophic denitrification. However, little is known on the loss processes affecting this prokaryotic group. In the present study, the protist grazing impact on the Sulfurimonas subgroup GD17 was determined for suboxic and oxygen/hydrogen sulphide interface depths of Baltic Sea redoxclines, using predator exclusion assays and bacterial amendment with the cultured representative 'Sulfurimonas gotlandica' strain GD1. Additionally, the principal bacterivores were identified by RNA-Stable Isotope Probing (RNA-SIP). The natural Sulfurimonas subgroup GD17 population grew strongly under oxygen/hydrogen sulphide interface conditions (doubling time: 1-1.5 days), but protist grazing could consume the complete new cell production per day. In suboxic samples, little or no growth of Sulfurimonas subgroup GD17 was observed. RNA-SIP identified five active grazers, belonging to typical redoxcline ciliates (Oligohymenophorea, Prostomatea) and globally widespread marine flagellate groups (MAST-4, Chrysophyta, Cercozoa). Overall, we demonstrate for the first time that protist grazing can control the growth, and potentially the vertical distribution, of a chemolithoautotrophic key-player of oxic/anoxic interfaces.
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Affiliation(s)
- Ruth Anderson
- Department of Biological Oceanography, Leibniz Institute for Baltic Sea Research, Seestrasse 15, 18119, Rostock-Warnemünde, Germany.
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49
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Filker S, Stock A, Breiner HW, Edgcomb V, Orsi W, Yakimov MM, Stoeck T. Environmental selection of protistan plankton communities in hypersaline anoxic deep-sea basins, Eastern Mediterranean Sea. Microbiologyopen 2012; 2:54-63. [PMID: 23239531 PMCID: PMC3584213 DOI: 10.1002/mbo3.56] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2012] [Revised: 10/31/2012] [Accepted: 11/12/2012] [Indexed: 11/25/2022] Open
Abstract
High salt concentrations, absence of light, anoxia, and high hydrostatic pressure make deep hypersaline anoxic basins (DHABs) in the Eastern Mediterranean Sea one of the most polyextreme habitats on Earth. Taking advantage of the unique chemical characteristics of these basins, we tested the effect of environmental selection and geographic distance on the structure of protistan communities. Terminal restriction fragment length polymorphism (T-RFLP) analyses were performed on water samples from the brines and seawater/brine interfaces of five basins: Discovery, Urania, Thetis, Tyro, and Medee. Using statistical analyses, we calculated the partitioning of diversity among the ten individual terminal restriction fragment (T-RF) profiles, based on peak abundance and peak incidence. While a significant distance effect on spatial protistan patterns was not detected, hydrochemical gradients emerged as strong dispersal barriers that likely lead to environmental selection in the DHAB protistan plankton communities. We identified sodium, magnesium, sulfate, and oxygen playing in concerto as dominant environmental drivers for the structuring of protistan plankton communities in the Eastern Mediterranean DHABs.
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Affiliation(s)
- Sabine Filker
- School of Biology, University of Kaiserslautern, Erwin-Schroedinger-Str. 14, D-67663, Kaiserslautern, Germany
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50
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Orsi W, Edgcomb V, Faria J, Foissner W, Fowle WH, Hohmann T, Suarez P, Taylor C, Taylor GT, Vd'ačný P, Epstein SS. Class Cariacotrichea, a novel ciliate taxon from the anoxic Cariaco Basin, Venezuela. Int J Syst Evol Microbiol 2012; 62:1425-1433. [PMID: 21841005 DOI: 10.1099/ijs.0.034710-0] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2023] Open
Abstract
The majority of environmental micro-organisms identified with the rRNA approach have never been visualized. Thus, their reliable classification and taxonomic assignment is often difficult or even impossible. In our preliminary 18S rRNA gene sequencing work from the world's largest anoxic marine environment, the Cariaco Basin (Caribbean Sea, Venezuela), we detected a ciliate clade, designated previously as CAR_H [Stoeck, S., Taylor, G. T. & Epstein, S. S. (2003). Appl Environ Microbiol 63, 5656-5663]. Here, we combine the traditional rRNA detection method of fluorescent in situ hybridization (FISH) with scanning electron microscopy (SEM) and confirm the phylogenetic separation of the CAR_H sequences from all other ciliate classes by showing an outstanding morphological feature of this group: a unique, archway-shaped kinety surrounding the oral apparatus and extending to the posterior body end in CAR_H cells. Based on this specific feature and the molecular phylogenies, we propose a novel ciliate class, Cariacotrichea nov. cl.
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Affiliation(s)
- William Orsi
- Department of Biology, Northeastern University, 313 Mugar Building, Boston, MA 02115, USA
| | - Virginia Edgcomb
- Department of Geology and Geophysics, Woods Hole Oceanographic Institution, Woods Hole, MA 02543, USA
| | - Jose Faria
- Departamento de Biología de Organismos, Universidad Simón Bolívar, Sartenejas, Baruta, Estado Miranda, Venezuela
| | - Wilhelm Foissner
- Department of Organismal Biology, University of Salzburg, Hellbrunnerstrasse 34, Salzburg, A 5020, Austria
| | - William H Fowle
- Department of Biology, Northeastern University, 313 Mugar Building, Boston, MA 02115, USA
| | - Tine Hohmann
- Department of Biology, Northeastern University, 313 Mugar Building, Boston, MA 02115, USA
| | - Paula Suarez
- Departamento de Biología de Organismos, Universidad Simón Bolívar, Sartenejas, Baruta, Estado Miranda, Venezuela
| | - Craig Taylor
- Department of Geology and Geophysics, Woods Hole Oceanographic Institution, Woods Hole, MA 02543, USA
| | - Gordon T Taylor
- Marine Sciences Research Center, State University of New York, Stony Brook, NY 11794, USA
| | - Peter Vd'ačný
- Department of Zoology, Comenius University, Mlynská dolina B-1, Bratislava, SK 84215, Slovak Republic
| | - Slava S Epstein
- Department of Biology, Northeastern University, 313 Mugar Building, Boston, MA 02115, USA
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