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Gross M, Dunthorn M, Mauvisseau Q, Stoeck T. Using digital PCR to predict ciliate abundance from ribosomal RNA gene copy numbers. Environ Microbiol 2024; 26:e16619. [PMID: 38649189 DOI: 10.1111/1462-2920.16619] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2023] [Accepted: 03/16/2024] [Indexed: 04/25/2024]
Abstract
Ciliates play a key role in most ecosystems. Their abundance in natural samples is crucial for answering many ecological questions. Traditional methods of quantifying individual species, which rely on microscopy, are often labour-intensive, time-consuming and can be highly biassed. As a result, we investigated the potential of digital polymerase chain reaction (dPCR) for quantifying ciliates. A significant challenge in this process is the high variation in the copy number of the taxonomic marker gene (ribosomal RNA [rRNA]). We first quantified the rRNA gene copy numbers (GCN) of the model ciliate, Paramecium tetraurelia, during different stages of the cell cycle and growth phases. The per-cell rRNA GCN varied between approximately 11,000 and 130,000, averaging around 50,000 copies per cell. Despite these variations in per-cell rRNA GCN, we found a highly significant correlation between GCN and cell numbers. This is likely due to the coexistence of different cellular stages in an uncontrolled (environmental) ciliate population. Thanks to the high sensitivity of dPCR, we were able to detect the target gene in a sample that contained only a single cell. The dPCR approach presented here is a valuable addition to the molecular toolbox in protistan ecology. It may guide future studies in quantifying and monitoring the abundance of targeted (even rare) ciliates in natural samples.
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Affiliation(s)
- Megan Gross
- Ecology Group, Rheinland-Pfälzische Technische Universität Kaiserslautern-Landau, Kaiserslautern, Germany
| | - Micah Dunthorn
- Natural History Museum, University of Oslo, Oslo, Norway
| | | | - Thorsten Stoeck
- Ecology Group, Rheinland-Pfälzische Technische Universität Kaiserslautern-Landau, Kaiserslautern, Germany
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2
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Abraham JS, Somasundaram S, Maurya S, Sood U, Lal R, Toteja R, Makhija S. Insights into freshwater ciliate diversity through high throughput DNA metabarcoding. FEMS MICROBES 2024; 5:xtae003. [PMID: 38450097 PMCID: PMC10917447 DOI: 10.1093/femsmc/xtae003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2023] [Revised: 01/03/2024] [Accepted: 02/21/2024] [Indexed: 03/08/2024] Open
Abstract
The freshwater bodies of India are highly biodiverse but still understudied, especially concerning ciliates. Ciliates constitute a significant portion of eukaryotic diversity and play crucial roles in microbial loops, nutrient recycling, and ecosystem maintenance. The present study aimed to elucidate ciliate diversity in three freshwater sites in the Delhi region of India: Okhla Bird Sanctuary (OBS), Sanjay Lake (SL), and Raj Ghat pond (RJ). This study represents the first investigation into the taxonomic diversity and richness of freshwater ciliates in India using a high-throughput DNA metabarcoding approach. For the analysis, total environmental DNA was extracted from the three freshwater samples, followed by sequencing of the 18S V4 barcode region and subsequent phylogenetic analyses. Operational taxonomic units (OTU) analyses revealed maximum species diversity in OBS (106), followed by SL (104) and RJ (99) sites. Ciliates from the classes Oligohymenophorea, Prostomatea, and Spirotrichea were dominant in the three sites. The study discusses the ability of the metabarcoding approach to uncover unknown and rare species. The study highlights the need for refined reference databases and cautious interpretation of the high-throughput sequencing-generated data while emphasizing the complementary nature of molecular and morphological approaches in studying ciliate diversity.
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Affiliation(s)
- Jeeva Susan Abraham
- Ciliate Biology Laboratory, Department of Zoology, Acharya Narendra Dev College, University of Delhi, Govindpuri, Kalkaji, New Delhi 110019, India
| | - Sripoorna Somasundaram
- Ciliate Biology Laboratory, Department of Zoology, Acharya Narendra Dev College, University of Delhi, Govindpuri, Kalkaji, New Delhi 110019, India
| | - Swati Maurya
- Ciliate Biology Laboratory, Department of Zoology, Acharya Narendra Dev College, University of Delhi, Govindpuri, Kalkaji, New Delhi 110019, India
| | - Utkarsh Sood
- Department of Zoology, Kirori Mal College, University of Delhi, Delhi 110007, India
| | - Rup Lal
- Ciliate Biology Laboratory, Department of Zoology, Acharya Narendra Dev College, University of Delhi, Govindpuri, Kalkaji, New Delhi 110019, India
| | - Ravi Toteja
- Ciliate Biology Laboratory, Department of Zoology, Acharya Narendra Dev College, University of Delhi, Govindpuri, Kalkaji, New Delhi 110019, India
| | - Seema Makhija
- Ciliate Biology Laboratory, Department of Zoology, Acharya Narendra Dev College, University of Delhi, Govindpuri, Kalkaji, New Delhi 110019, India
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3
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Owens LA, Friant S, Martorelli Di Genova B, Knoll LJ, Contreras M, Noya-Alarcon O, Dominguez-Bello MG, Goldberg TL. VESPA: an optimized protocol for accurate metabarcoding-based characterization of vertebrate eukaryotic endosymbiont and parasite assemblages. Nat Commun 2024; 15:402. [PMID: 38195557 PMCID: PMC10776621 DOI: 10.1038/s41467-023-44521-3] [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: 04/04/2023] [Accepted: 12/15/2023] [Indexed: 01/11/2024] Open
Abstract
Protocols for characterizing taxonomic assemblages by deep sequencing of short DNA barcode regions (metabarcoding) have revolutionized our understanding of microbial communities and are standardized for bacteria, archaea, and fungi. Unfortunately, comparable methods for host-associated eukaryotes have lagged due to technical challenges. Despite 54 published studies, issues remain with primer complementarity, off-target amplification, and lack of external validation. Here, we present VESPA (Vertebrate Eukaryotic endoSymbiont and Parasite Analysis) primers and optimized metabarcoding protocol for host-associated eukaryotic community analysis. Using in silico prediction, panel PCR, engineered mock community standards, and clinical samples, we demonstrate VESPA to be more effective at resolving host-associated eukaryotic assemblages than previously published methods and to minimize off-target amplification. When applied to human and non-human primate samples, VESPA enables reconstruction of host-associated eukaryotic endosymbiont communities more accurately and at finer taxonomic resolution than microscopy. VESPA has the potential to advance basic and translational science on vertebrate eukaryotic endosymbiont communities, similar to achievements made for bacterial, archaeal, and fungal microbiomes.
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Affiliation(s)
- Leah A Owens
- Department of Pathobiological Sciences, School of Veterinary Medicine, University of Wisconsin-Madison, Madison, WI, USA.
| | - Sagan Friant
- Department of Pathobiological Sciences, School of Veterinary Medicine, University of Wisconsin-Madison, Madison, WI, USA
- Department of Anthropology, The Pennsylvania State University, University Park, PA, USA
- Huck Institutes of the Life Sciences, The Pennsylvania State University, University Park, PA, USA
| | - Bruno Martorelli Di Genova
- Department of Medical Microbiology and Immunology, University of Wisconsin-Madison, Madison, WI, USA
- Department of Microbiology and Molecular Genetics, Larner College of Medicine, The University of Vermont, Burlington, VT, USA
| | - Laura J Knoll
- Department of Medical Microbiology and Immunology, University of Wisconsin-Madison, Madison, WI, USA
| | - Monica Contreras
- Center for Biophysics and Biochemistry, Venezuelan Institute of Scientific Research (IVIC), Caracas, Venezuela
| | - Oscar Noya-Alarcon
- Centro Amazónico de Investigación y Control de Enfermedades Tropicales-CAICET, Puerto Ayacucho, Amazonas, Venezuela
| | - Maria G Dominguez-Bello
- Department of Biochemistry and Microbiology, Rutgers University-New Brunswick, New Brunswick, NJ, USA
- Department of Anthropology, Rutgers University, New Brunswick, NJ, USA
- Institute for Food, Nutrition and Health, Rutgers University, New Brunswick, NJ, USA
- Canadian Institute for Advanced Research (CIFAR), Toronto, ON, Canada
| | - Tony L Goldberg
- Department of Pathobiological Sciences, School of Veterinary Medicine, University of Wisconsin-Madison, Madison, WI, USA.
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4
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Lian C, Zhao Y, Li P, Zhang T, Al-Rasheid KAS, Stover NA, Wang Y, Shao C. Three closely-related subclasses Phacodiniidia Small & Lynn, 1985, Protohypotrichia Shi et al., 1999, and Euplotia Jankowski, 1979 (Protista, Ciliophora): A new contribution to their phylogeny with reconsiderations on the evolutionary hypotheses. Mol Phylogenet Evol 2023; 189:107936. [PMID: 37778530 DOI: 10.1016/j.ympev.2023.107936] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2023] [Revised: 09/28/2023] [Accepted: 09/28/2023] [Indexed: 10/03/2023]
Abstract
The huge variety of species and worldwide distribution of ciliated protists in class Spirotrichea continue to make it one of the most complicated and confused groups in Ciliophora, despite significant research interest in the unique molecular genetics of these organisms. In this study, the morphological and molecular information were integrated, and it is inferred from a new perspective for the evolutionary relationship among Phacodiniidia, Protohypotrichia, Hypotrichia and Euplotia. Our results indicate that Kiitricha and Caryotricha, two members in Protohypotrichia, may represent two parallel branches of evolution; Euplotidae and Aspidiscidae represent the most recently diverged taxa within Euplotida, followed by Certesiidae, Gastrocirrhidae, and Uronychidae. Further, representative morphological characters (e.g. fronto-ventral-transverse cirral anlagen, undulating membranes, marginal cirri and caudal cirri) were stochastically mapped on phylogenies to speculate evolutionary path and morphological characters of the evolutionary transition node groups were assumed.
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Affiliation(s)
- Chunyu Lian
- Laboratory of Protozoological Biodiversity and Evolution in Wetland, College of Life Sciences, Shaanxi Normal University, Xi'an 710119, China
| | - Yan Zhao
- College of Life Sciences, Capital Normal University, Beijing 100048, China
| | - Ping Li
- Powerchina Northwest Engineering Corporation Limited, Xi'an 710065, China
| | - Tengteng Zhang
- Laboratory of Protozoological Biodiversity and Evolution in Wetland, College of Life Sciences, Shaanxi Normal University, Xi'an 710119, China
| | - Khaled A S Al-Rasheid
- Zoology Department, College of Science, King Saud University, Riyadh 11451, Saudi Arabia
| | - Naomi A Stover
- Department of Biology, Bradley University, Peoria 61625, USA
| | - Yurui Wang
- Laboratory of Protozoological Biodiversity and Evolution in Wetland, College of Life Sciences, Shaanxi Normal University, Xi'an 710119, China.
| | - Chen Shao
- Laboratory of Protozoological Biodiversity and Evolution in Wetland, College of Life Sciences, Shaanxi Normal University, Xi'an 710119, China.
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Marinchel N, Marchesini A, Nardi D, Girardi M, Casabianca S, Vernesi C, Penna A. Mock community experiments can inform on the reliability of eDNA metabarcoding data: a case study on marine phytoplankton. Sci Rep 2023; 13:20164. [PMID: 37978238 PMCID: PMC10656442 DOI: 10.1038/s41598-023-47462-5] [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: 04/29/2023] [Accepted: 11/14/2023] [Indexed: 11/19/2023] Open
Abstract
Environmental DNA metabarcoding is increasingly implemented in biodiversity monitoring, including phytoplankton studies. Using 21 mock communities composed of seven unicellular diatom and dinoflagellate algae, assembled with different composition and abundance by controlling the number of cells, we tested the accuracy of an eDNA metabarcoding protocol in reconstructing patterns of alpha and beta diversity. This approach allowed us to directly evaluate both qualitative and quantitative metabarcoding estimates. Our results showed non-negligible rates (17-25%) of false negatives (i.e., failure to detect a taxon in a community where it was included), for three taxa. This led to a statistically significant underestimation of metabarcoding-derived alpha diversity (Wilcoxon p = 0.02), with the detected species richness being lower than expected (based on cell numbers) in 8/21 mock communities. Considering beta diversity, the correlation between metabarcoding-derived and expected community dissimilarities was significant but not strong (R2 = 0.41), indicating suboptimal accuracy of metabarcoding results. Average biovolume and rDNA gene copy number were estimated for the seven taxa, highlighting a potential, though not exhaustive, role of the latter in explaining the recorded biases. Our findings highlight the importance of mock communities for assessing the reliability of phytoplankton eDNA metabarcoding studies and identifying their limitations.
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Affiliation(s)
- Nadia Marinchel
- Department of Pure and Applied Sciences, University of Urbino, Urbino, Italy.
- Department of Biomolecular Sciences, University of Urbino, Urbino, Italy.
| | - Alexis Marchesini
- Research Institute on Terrestrial Ecosystems (IRET), National Research Council (CNR), Porano, Italy
- National Biodiversity Future Center, Palermo, Italy
| | - Davide Nardi
- DAFNAE, University of Padova, Legnaro, PD, Italy
| | - Matteo Girardi
- Conservation Genomics Research Unit, Research and Innovation Centre, Fondazione Edmund Mach, S. Michele all'Adige, Italy
| | - Silvia Casabianca
- Department of Biomolecular Sciences, University of Urbino, Urbino, Italy
- Fano Marine Center, Inter-Institute Center for Research on Marine Biodiversity, Resources and Biotechnologies, Fano, Italy
- CoNISMa, National Inter-University Consortium for Marine Sciences, Rome, Italy
| | - Cristiano Vernesi
- National Biodiversity Future Center, Palermo, Italy
- Forest Ecology Unit, Research and Innovation Centre, Fondazione Edmund Mach, S. Michele all'Adige, Italy
| | - Antonella Penna
- Department of Biomolecular Sciences, University of Urbino, Urbino, Italy.
- Fano Marine Center, Inter-Institute Center for Research on Marine Biodiversity, Resources and Biotechnologies, Fano, Italy.
- CoNISMa, National Inter-University Consortium for Marine Sciences, Rome, Italy.
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6
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Morin F, Panova MAZ, Schweizer M, Wiechmann M, Eliassen N, Sundberg P, Cluzel-Burgalat L, Polovodova Asteman I. Hidden aliens: Application of digital PCR to track an exotic foraminifer across the Skagerrak (North Sea) correlates well with traditional morphospecies analysis. Environ Microbiol 2023; 25:2321-2337. [PMID: 37393907 DOI: 10.1111/1462-2920.16458] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2023] [Accepted: 06/14/2023] [Indexed: 07/04/2023]
Abstract
The problem of invasive species is a well-studied one, but knowledge of free-living unicellular eukaryotic invasive species is lacking. A potentially invasive foraminifer (Rhizaria), Nonionella sp. T1, was recently discovered in the Skagerrak and its fjords. Digital polymerase chain reaction (dPCR) was applied to track the spread of this non-indigenous species using a new dPCR assay (T1-1). The use of dPCR appears highly complementary to traditional hand picking of foraminiferal shells from the sediment, and is far less time-consuming. This study indicates that Nonionella sp. T1 has bypassed the outer Skagerrak strait, instead becoming established in Swedish west coast fjords, constituting up to half of the living foraminiferal community in fjord mouth areas. The ecology of Nonionella sp. T1 and its potential invasive impacts are still largely unknown, but it appears to be an opportunist using several energy sources such as nitrate respiration and kleptoplasty along with a possibly more efficient reproductive strategy to gain an advantage over the native foraminiferal species. Future ecological studies of Nonionella sp. T1 could be aided by dPCR and the novel Nonionella sp. T1-specific T1-1 assay.
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Affiliation(s)
- Filip Morin
- Department of Marine Science, University of Gothenburg, Gothenburg, Sweden
| | - Marina Antonina Zoe Panova
- Department of Marine Science, University of Gothenburg, Gothenburg, Sweden
- SeAnalytics AB, Gothenburg, Sweden
| | - Magali Schweizer
- Laboratory of Planetology and Geosciences (LPG) UMR6112, University of Angers, CNRS, Angers, France
- Laboratory of Planetology and Geosciences (LPG), Nantes University, CNRS, Nantes, France
- Laboratory of Planetology and Geosciences (LPG), Le Mans University, CNRS, Le Mans, France
| | - Marlene Wiechmann
- Department of Marine Science, University of Gothenburg, Gothenburg, Sweden
| | - Nicole Eliassen
- Department of Marine Science, University of Gothenburg, Gothenburg, Sweden
| | - Per Sundberg
- Department of Marine Science, University of Gothenburg, Gothenburg, Sweden
- SeAnalytics AB, Gothenburg, Sweden
| | | | - Irina Polovodova Asteman
- Department of Marine Science, University of Gothenburg, Gothenburg, Sweden
- Gothenburg Global Biodiversity Centre, University of Gothenburg, Gothenburg, Sweden
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Ruvindy R, Barua A, Bolch CJS, Sarowar C, Savela H, Murray SA. Genomic copy number variability at the genus, species and population levels impacts in situ ecological analyses of dinoflagellates and harmful algal blooms. ISME COMMUNICATIONS 2023; 3:70. [PMID: 37422553 PMCID: PMC10329664 DOI: 10.1038/s43705-023-00274-0] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/23/2022] [Revised: 06/18/2023] [Accepted: 06/20/2023] [Indexed: 07/10/2023]
Abstract
The application of meta-barcoding, qPCR, and metagenomics to aquatic eukaryotic microbial communities requires knowledge of genomic copy number variability (CNV). CNV may be particularly relevant to functional genes, impacting dosage and expression, yet little is known of the scale and role of CNV in microbial eukaryotes. Here, we quantify CNV of rRNA and a gene involved in Paralytic Shellfish Toxin (PST) synthesis (sxtA4), in 51 strains of 4 Alexandrium (Dinophyceae) species. Genomes varied up to threefold within species and ~7-fold amongst species, with the largest (A. pacificum, 130 ± 1.3 pg cell-1 /~127 Gbp) in the largest size category of any eukaryote. Genomic copy numbers (GCN) of rRNA varied by 6 orders of magnitude amongst Alexandrium (102- 108 copies cell-1) and were significantly related to genome size. Within the population CNV of rRNA was 2 orders of magnitude (105 - 107 cell-1) in 15 isolates from one population, demonstrating that quantitative data based on rRNA genes needs considerable caution in interpretation, even if validated against locally isolated strains. Despite up to 30 years in laboratory culture, rRNA CNV and genome size variability were not correlated with time in culture. Cell volume was only weakly associated with rRNA GCN (20-22% variance explained across dinoflagellates, 4% in Gonyaulacales). GCN of sxtA4 varied from 0-102 copies cell-1, was significantly related to PSTs (ng cell-1), displaying a gene dosage effect modulating PST production. Our data indicate that in dinoflagellates, a major marine eukaryotic group, low-copy functional genes are more reliable and informative targets for quantification of ecological processes than unstable rRNA genes.
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Affiliation(s)
- Rendy Ruvindy
- University of Technology Sydney, School of Life Sciences, Sydney, PO Box 123, Broadway, NSW, 2007, Australia
| | - Abanti Barua
- University of Technology Sydney, School of Life Sciences, Sydney, PO Box 123, Broadway, NSW, 2007, Australia
| | - Christopher J S Bolch
- Institute for Marine & Antarctic Studies, University of Tasmania, Launceston, 7248, TAS, Australia
| | - Chowdhury Sarowar
- Sydney Institute of Marine Science, Chowder Bay Rd, Mosman, NSW, Australia
| | - Henna Savela
- University of Technology Sydney, School of Life Sciences, Sydney, PO Box 123, Broadway, NSW, 2007, Australia
- Finnish Environment Institute, Marine Research Centre, Helsinki, Finland
| | - Shauna A Murray
- University of Technology Sydney, School of Life Sciences, Sydney, PO Box 123, Broadway, NSW, 2007, Australia.
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Ciliate Morpho-Taxonomy and Practical Considerations before Deploying Metabarcoding to Ciliate Community Diversity Surveys in Urban Receiving Waters. Microorganisms 2022; 10:microorganisms10122512. [PMID: 36557765 PMCID: PMC9787992 DOI: 10.3390/microorganisms10122512] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2022] [Revised: 12/12/2022] [Accepted: 12/12/2022] [Indexed: 12/23/2022] Open
Abstract
Disentangling biodiversity and community assembly effects on ecosystem function has always been an important topic in ecological research. The development and application of a DNA metabarcoding method has fundamentally changed the way we describe prokaryotic communities and estimate biodiversity. Compared to prokaryotes (bacteria and archaea), the eukaryotic microbes (unicellular eukaryotes) also fulfill extremely important ecological functions in different ecosystems regarding their intermediate trophic positions. For instance, ciliated microbes (accounting for a substantial portion of the diversity of unicellular eukaryotes) perform pivotal roles in microbial loops and are essential components in different ecosystems, especially in water purification processes. Therefore, the community composition of ciliated species has been widely utilized as a proxy for water quality and biological assessment in urban river ecosystems and WWTPs (wastewater treatment plants). Unfortunately, investigating the dynamic changes and compositions in ciliate communities relies heavily on existing morpho-taxonomical descriptions, which is limited by traditional microscopic approaches. To deal with this dilemma, we discuss the DNA-based taxonomy of ciliates, the relative merits and challenges of deploying its application using DNA metabarcoding for surveys of ciliate community diversity in urban waterbodies, and provide suggestions for minimizing relevant sources of biases in its implementation. We expect that DNA metabarcoding could untangle relationships between community assembly and environmental changes affecting ciliate communities. These analyses and discussions could offer a replicable method in support of the application of evaluating communities of ciliated protozoa as indicators of urban freshwater ecosystems.
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Iniesto M, Moreira D, Benzerara K, Reboul G, Bertolino P, Tavera R, López‐García P. Planktonic microbial communities from microbialite-bearing lakes sampled along a salinity-alkalinity gradient. LIMNOLOGY AND OCEANOGRAPHY 2022; 67:2718-2733. [PMID: 37064594 PMCID: PMC10087431 DOI: 10.1002/lno.12233] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/20/2022] [Revised: 07/12/2022] [Accepted: 09/04/2022] [Indexed: 06/19/2023]
Abstract
Continental freshwater systems are particularly vulnerable to environmental variation. Climate change-induced desertification and the anthropogenic exploitation of hydric resources result in the progressive evaporation and salinization of inland water bodies in many areas of the globe. However, how this process impacts microbial communities and their activities in biogeochemical cycles is poorly known. Here, we take a space-for-time substitution approach and characterize the prokaryotic and eukaryotic microbial communities of two planktonic cell-size fractions (0.2-5 μm and 5-30 μm) from lakes of diverse trophic levels sampled along a salinity-alkalinity gradient located in the Trans-Mexican Volcanic Belt (TMVB). We applied a 16S/18S rRNA gene metabarcoding strategy to determine the microbial community composition of 54 samples from 12 different lakes, from the low-salinity lake Zirahuén to the hypersaline residual ponds of Rincón de Parangueo. Except for systems at both extremes of the salinity gradient, most lakes along the evaporation trend bear actively forming microbialites, which harbor microbial communities clearly distinct from those of plankton. Several lakes were sampled in winter and late spring and the crater lakes Alchichica and Atexcac were sampled across the water column. Physicochemical parameters related to salinity-alkalinity were the most influential drivers of microbial community structure whereas trophic status, depth, or season were less important. Our results suggest that climate change and anthropogenic-induced hydric deficit could significantly affect microbial communities, potentially altering ecosystem functioning.
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Affiliation(s)
- Miguel Iniesto
- Ecologie Systématique Evolution, CNRSUniversité Paris‐Saclay, AgroParisTechOrsayFrance
| | - David Moreira
- Ecologie Systématique Evolution, CNRSUniversité Paris‐Saclay, AgroParisTechOrsayFrance
| | - Karim Benzerara
- Institut de Minéralogie de Physique des Matériaux et de Cosmochimie, CNRSSorbonne Université, Muséum National d'Histoire NaturelleParisFrance
| | - Guillaume Reboul
- Ecologie Systématique Evolution, CNRSUniversité Paris‐Saclay, AgroParisTechOrsayFrance
| | - Paola Bertolino
- Ecologie Systématique Evolution, CNRSUniversité Paris‐Saclay, AgroParisTechOrsayFrance
| | - Rosaluz Tavera
- Departamento de Ecología y Recursos NaturalesUniversidad Nacional Autónoma de MéxicoMexico CityMexico
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10
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Zhang G, Sheng Y, Liu Y, Cao X, Al-Farraj SA, Vďačný P, Pan H. Integrative studies on three new freshwater Amphileptus species (Ciliophora, Pleurostomatida) discovered in northern China. MARINE LIFE SCIENCE & TECHNOLOGY 2022; 4:452-470. [PMID: 37078086 PMCID: PMC10077290 DOI: 10.1007/s42995-022-00143-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/17/2022] [Accepted: 08/23/2022] [Indexed: 05/03/2023]
Abstract
The morphology and molecular phylogeny of freshwater pleurostomatid ciliates are insufficiently explored. In the present study, we investigated three new Amphileptus species discovered in Lake Weishan and its vicinity, northern China, using standard alpha-taxonomic methods. Amphileptus paracarchesii sp. nov. is characterized by a lateral fossa (groove) in the posterior body portion, four macronuclear nodules, contractile vacuoles distributed along the dorsal margin, and 4-6 left and 44-50 right somatic kineties. Amphileptus pilosus sp. nov. differs from congeners by having 4-14 macronuclear nodules, numerous contractile vacuoles scattered throughout the cytoplasm, and 22-31 left and 35-42 right somatic kineties. Amphileptus orientalis sp. nov. is characterized by two ellipsoidal macronuclear nodules, three ventral contractile vacuoles, and about four left and 31-35 right somatic kineties. Phylogenetic analyses of nuclear small subunit ribosomal DNA (SSU rDNA) sequences indicate that the family Amphileptidae might be monophyletic while the genus Amphileptus is paraphyletic, as Pseudoamphileptus macrostoma robustly groups with Amphileptus sp. Although deep phylogenetic relationships of amphileptids are poorly resolved, multiple well-delimited species groups are recognizable within the genus Amphileptus. Supplementary Information The online version contains supplementary material available at 10.1007/s42995-022-00143-0.
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Affiliation(s)
- Gongaote Zhang
- Engineering Research Center of Environmental DNA and Ecological Water Health Assessment, Shanghai Ocean University, Shanghai, 201306 China
- Institute of Evolution and Marine Biodiversity, Ocean University of China, Qingdao, 266003 China
| | - Yalan Sheng
- Guangzhou Key Laboratory of Subtropical Biodiversity and Biomonitoring, School of Life Science, South China Normal University, Guangzhou, 510631 China
| | - Yujie Liu
- Institute of Evolution and Marine Biodiversity, Ocean University of China, Qingdao, 266003 China
| | - Xiao Cao
- Weishan Fishery Development Service Center, Jining, 277600 China
| | - Saleh A. Al-Farraj
- Zoology Department, College of Science, King Saud University, Riyadh, 11451 Saudi Arabia
| | - Peter Vďačný
- Department of Zoology, Comenius University in Bratislava, Bratislava, 84215 Slovakia
| | - Hongbo Pan
- Engineering Research Center of Environmental DNA and Ecological Water Health Assessment, Shanghai Ocean University, Shanghai, 201306 China
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11
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Li B, Song Y, Hao T, Wang L, Zheng W, lyu Z, Chen Y, Pan X. Insights into the phylogeny of the ciliate of class Colpodea based on multigene data. Ecol Evol 2022; 12:e9380. [PMID: 36304093 PMCID: PMC9595136 DOI: 10.1002/ece3.9380] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2022] [Revised: 08/29/2022] [Accepted: 09/15/2022] [Indexed: 11/26/2022] Open
Abstract
In the class Colpodea, there are many unresolved evolutionary relationships among taxa. Here, we report 30 new sequences including SSU‐rRNA, ITS1‐5.8S‐ ITS2 rRNA, and the mitochondrial small subunit ribosomal RNA (mtSSU‐rRNA) genes of five colpodeans, and conduct phylogenetic analyses based on each individual gene and a two‐gene concatenated dataset. For the first time, multi‐genes were used to analyze phylogenetic relationships in the class Colpodea. The main findings are: (1) SSU‐rRNA, ITS1‐5.8S‐ ITS2 rRNA, and mtSSU‐rRNA gene sequences of C. reniformis and C. grandis are provided for the first time, and these two species group into the clade including C. inflata, C. lucida, C. cucullus, and C. henneguyi; (2) clustering pattern and morphological similarity indicate that Bresslauides discoideus has a close relation with Colpodidae spp.; (3) Emarginatophrya genus diagnosis is improved to be ‘Hausmanniellidae with sharply shortened and isometric leftmost 1‐4 ciliary rows’ and Colpoda elliotti is transferred to Emarginatophrya; (4) the genus Colpoda is still non‐monophyletic with the addition of 10 populations from five Colpoda species sequences, but there are only two Colpoda groups left based on the present work: Group I comprises C. inflata, C. lucida, C. cucullus, C. henneguyi, C. reniformis, and C. grandis, Group II comprises C. maupasi and C. ecaudata, and the presence of diagonal grooves and the way the vestibular opens might be the two key features that differentiates Colpoda species groups; (5) a close molecular relationship, and highly similar merotelokinetal mode, somatic ciliary pattern, and basic organization of the oral apparatus with P. steinii suggests Bromeliothrix metopoides should be temporarily assigned to Colpodidae.
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Affiliation(s)
- Bailin Li
- Key Laboratory of Biodiversity of Aquatic OrganismsHarbin Normal University HarbinHarbinP. R. China
| | - Yumeng Song
- Key Laboratory of Biodiversity of Aquatic OrganismsHarbin Normal University HarbinHarbinP. R. China
| | - Tingting Hao
- Key Laboratory of Biodiversity of Aquatic OrganismsHarbin Normal University HarbinHarbinP. R. China
| | - Li Wang
- Key Laboratory of Biodiversity of Aquatic OrganismsHarbin Normal University HarbinHarbinP. R. China
| | - Weibin Zheng
- Key Laboratory of Biodiversity of Aquatic OrganismsHarbin Normal University HarbinHarbinP. R. China
| | - Zhao lyu
- College of Life SciencesNorthwest UniversityXi'anChina
| | - Ying Chen
- School of Civil and Environmental EngineeringHarbin Institute of Technology (Shenzhen)ShenzhenChina
| | - Xuming Pan
- Key Laboratory of Biodiversity of Aquatic OrganismsHarbin Normal University HarbinHarbinP. R. China
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12
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Zhang Y, Li F, Chen Y, Guan LL. The Effects of Breed and Residual Feed Intake Divergence on the Abundance and Active Population of Rumen Microbiota in Beef Cattle. Animals (Basel) 2022; 12:ani12151966. [PMID: 35953955 PMCID: PMC9367312 DOI: 10.3390/ani12151966] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2022] [Revised: 07/30/2022] [Accepted: 08/01/2022] [Indexed: 11/16/2022] Open
Abstract
To assess the effects of residual feed intake (RFI) and breed on rumen microbiota, the abundance (DNA) and active population (RNA) of the total bacteria, archaea, protozoa, and fungi in the rumen of 96 beef steers from three different breeds (Angus (AN), Charolais (CH), and Kinsella Composite (KC)), and divergent RFIs (High vs Low), were estimated by measuring their respective maker gene copies using qRT-PCR. All experimental animals were kept under the same feedlot condition and fed with the same high-energy finishing diet. Rumen content samples were collected at slaughter and used for the extraction of genetic material (DNA and RNA) and further analysis. There was a significant difference (p < 0.01) between the marker gene copies detected for abundance and active populations for all four microbial groups. AN steers had a higher abundance of bacteria (p < 0.05) and a lower abundance of eukaryotes (protozoa and fungi, p < 0.05) compared to KC steers, while the abundance of protozoa (p < 0.05) in the AN cattle and fungi (p < 0.05) in the KC cattle were lower and higher, respectively, than those in the CH steers. Meanwhile, the active populations of bacteria, archaea, and protozoa in the KC steers were significantly lower than those in the AN and CH animals (p < 0.01). This work demonstrates that cattle breed can affect rumen microbiota at both the abundance and activity level. The revealed highly active protozoal populations indicate their important role in rumen microbial fermentation under a feedlot diet, which warrants further study.
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Affiliation(s)
- Yawei Zhang
- College of Animal Science, Shanxi Agricultural University, Taiyuan 030031, China;
| | - Fuyong Li
- Department of Agricultural, Food and Nutritional Science, University of Alberta, Edmonton, AB T6G 2P5, Canada; (F.L.); (Y.C.)
| | - Yanhong Chen
- Department of Agricultural, Food and Nutritional Science, University of Alberta, Edmonton, AB T6G 2P5, Canada; (F.L.); (Y.C.)
| | - Le-Luo Guan
- Department of Agricultural, Food and Nutritional Science, University of Alberta, Edmonton, AB T6G 2P5, Canada; (F.L.); (Y.C.)
- Correspondence:
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13
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Morphology and Molecular Phylogeny of Fuscheriides baugilensis sp. nov. (Protozoa, Ciliophora, Haptorida) from South Korea. DIVERSITY 2022. [DOI: 10.3390/d14020070] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
The morphology and molecular phylogeny of a new haptorid ciliate, Fuscheriides baugilensis sp. nov., discovered in a temporary pond in South Korea, were investigated. The new species is characterized by its small body size (30–55 × 15–20 μm in vivo), oblong to rod-shaped extrusomes in the oral bulge and cytoplasm, 14–16 somatic kineties, two dorsal brush rows, and single subapical ciliary condensation. The phylogenetic analyses based on the 18S rRNA gene sequences show that the family Fuscheriidae is paraphyletic and the species belong to the genera Fuscheriides and Pseudofuscheria cluster together in the same subclade, while Fuscheria is in a different subclade, suggesting that the subapical ciliary condensation characterizing the two former genera has a higher taxonomic value than the shape of extrusomes for genera separation.
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14
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Zou S, Fu R, Deng H, Zhang Q, Gentekaki E, Gong J. Coupling between Ribotypic and Phenotypic Traits of Protists across Life Cycle Stages and Temperatures. Microbiol Spectr 2021; 9:e0173821. [PMID: 34817220 PMCID: PMC8612162 DOI: 10.1128/spectrum.01738-21] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2021] [Accepted: 10/16/2021] [Indexed: 01/04/2023] Open
Abstract
Relationships between ribotypic and phenotypic traits of protists across life cycle stages remain largely unknown. Herein, we used single cells of two soil and two marine ciliate species to examine phenotypic and ribotypic traits and their relationships across lag, log, plateau, cystic stages and temperatures. We found that Colpoda inflata and Colpoda steinii demonstrated allometric relationships between 18S ribosomal DNA (rDNA) copy number per cell (CNPC), cell volume (CV), and macronuclear volume across all life cycle stages. Integrating previously reported data of Euplotes vannus and Strombidium sulcatum indicated taxon-dependent rDNA CNPC-CV functions. Ciliate and prokaryote data analysis revealed that the rRNA CNPC followed a unified power-law function only if the rRNA-deficient resting cysts were not considered. Hence, a theoretical framework was proposed to estimate the relative quantity of resting cysts in the protistan populations with total cellular rDNA and rRNA copy numbers. Using rDNA CNPC was a better predictor of growth rate at a given temperature than rRNA CNPC and CV, suggesting replication of redundant rDNA operons as a key factor that slows cell division. Single-cell high-throughput sequencing and analysis after correcting sequencing errors revealed multiple rDNA and rRNA variants per cell. Both encystment and temperature affected the number of rDNA and rRNA variants in several cases. The divergence of rDNA and rRNA sequence in a single cell ranged from 1% to 10% depending on species. These findings have important implications for inferring cell-based biological traits (e.g., species richness, abundance and biomass, activity, and community structure) of protists using molecular approaches. IMPORTANCE Based on phenotypic traits, traditional surveys usually characterize organismal richness, abundance, biomass, and growth potential to describe diversity, organization, and function of protistan populations and communities. The rRNA gene (rDNA) and its transcripts have been widely used as molecular markers in ecological studies of protists. Nevertheless, the manner in which these molecules relate to cellular (organismal) and physiological traits remains poorly understood, which could lead to misinterpretations of protistan diversity and ecology. The current research highlights the dynamic nature of cellular rDNA and rRNA contents, which tightly couple with multiple phenotypic traits in ciliated protists. We demonstrate that quantity of resting cysts and maximum growth rate of a population can be theoretically estimated using ribotypic trait-based models. The intraindividual sequence polymorphisms of rDNA and rRNA can be influenced by encystment and temperature, which should be considered when interpreting species-level diversity and community structure of microbial eukaryotes.
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Affiliation(s)
- Songbao Zou
- Yantai Institute of Coastal Zone Research, Chinese Academy of Sciences, Yantai, China
- University of Chinese Academy of Sciences, Beijing, China
- Key Laboratory of Healthy Freshwater Aquaculture, Ministry of Agriculture and Rural Affairs, Huzhou, China
- Key Laboratory of Fish Health and Nutrition of Zhejiang Province, Zhejiang Institute of Freshwater Fisheries, Huzhou, China
| | - Rao Fu
- Yantai Institute of Coastal Zone Research, Chinese Academy of Sciences, Yantai, China
- University of Chinese Academy of Sciences, Beijing, China
- Shandong Institute of Sericulture, Shandong Academy of Agricultural Sciences, Yantai, China
| | - Huiwen Deng
- School of Marine Sciences, Sun Yat-sen University, Zhuhai, China
- Southern Marine Science and Engineering Guangdong Laboratory, Zhuhai, China
| | - Qianqian Zhang
- Yantai Institute of Coastal Zone Research, Chinese Academy of Sciences, Yantai, China
- University of Chinese Academy of Sciences, Beijing, China
| | - Eleni Gentekaki
- School of Science, Mae Fah Luang University, Chiang Rai, Thailand
| | - Jun Gong
- School of Marine Sciences, Sun Yat-sen University, Zhuhai, China
- Southern Marine Science and Engineering Guangdong Laboratory, Zhuhai, China
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15
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Liu Y, Hu Z, Deng Y, Shang L, Gobler CJ, Tang YZ. Dependence of genome size and copy number of rRNA gene on cell volume in dinoflagellates. HARMFUL ALGAE 2021; 109:102108. [PMID: 34815026 DOI: 10.1016/j.hal.2021.102108] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/08/2020] [Revised: 09/13/2021] [Accepted: 09/16/2021] [Indexed: 06/13/2023]
Abstract
Dinoflagellates are an ecologically important group of protists in aquatic environment and have evolved many unusual and enigmatic genomic features such as immense genome sizes, high repeated genes, and a large portion of hydroxymethyluracil in DNA. Although previous studies have observed positive correlations between the large subunit (LSU) rRNA gene copy number and genome size of a variety of eukaryotic organisms (e.g. higher plants and animals), or between cell volume and LSU rRNA gene copy number, and/or between genome size and cell size, which suggests a possible co-evolution among these three features in different lineages of life, it remains an open question regarding the relationships among these three parameters in dinoflagellates. For the first time, we estimated the copy numbers of the LSU rRNA gene, the genome sizes, and cell volumes within a broad range of dinoflagellates (covering 15 species of 11 genera) using single-cell qPCR-based assay (determining LSU rRNA gene copy number), FlowCAM (cell volume measurement), and ultraviolet spectrophotometry (genome size estimation). The measured copy number of LSU rRNA gene ranged from 398 ± 184 (Prorocentrum minimum) to 152,078 ± 33,555 copies•cell-1 (Alexandrium pacificum), while the genome size and the cell volume ranged from 5.6 ± 0.2 (Karlodinium veneficum) to 853 ± 19.9 pg•cell-1 (Pseliodinium pirum), and from 1,070 ± 225 (Kar. veneficum) to 168,474 ± 124,180 μm3 (Ps. pirum), respectively. Together with the three parameters measured in literature, there are significant positive linear correlations between LSU rRNA gene copy numbers and genome sizes, cell volumes and LSU rRNA gene copy numbers, and between genome sizes and cell volumes via comparisons of multi-model regression analyses, suggesting a dependence of genome size and rRNA gene copy number on the cell volumes of dinoflagellates. Validation of the measurement methods was conducted via comparisons between reported data in the literature and that predicted using the linear equations we obtained, and between genome size measured by flow cytometry (FCM) and ultraviolet spectrophotometry (Nanodrop). These results provide insightful understandings of dinoflagellate evolution in terms of the relationships among genomes, gene copy number, and cell volume, and of rRNA gene-based studies in intra-populational and intra-individual genetic diversity, taxonomy, and diversity assessment in the environment of dinoflagellates. The results also provide a dataset useful for reads calibration in environmental metabarcoding studies of dinoflagellates and selection of candidate species for whole genome sequencing.
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Affiliation(s)
- Yuyang Liu
- CAS Key Laboratory of Marine Ecology and Environmental Sciences, Institute of Oceanology, Chinese Academy of Sciences, 7 Nanhai Road, Qingdao 266071, China
| | - Zhangxi Hu
- CAS Key Laboratory of Marine Ecology and Environmental Sciences, Institute of Oceanology, Chinese Academy of Sciences, 7 Nanhai Road, Qingdao 266071, China; Laboratory for Marine Ecology and Environmental Science, Qingdao National Laboratory for Marine Science and Technology, Qingdao 266237, China; Center for Ocean Mega-Science, Chinese Academy of Sciences, Qingdao 266071, China.
| | - Yunyan Deng
- CAS Key Laboratory of Marine Ecology and Environmental Sciences, Institute of Oceanology, Chinese Academy of Sciences, 7 Nanhai Road, Qingdao 266071, China; Laboratory for Marine Ecology and Environmental Science, Qingdao National Laboratory for Marine Science and Technology, Qingdao 266237, China; Center for Ocean Mega-Science, Chinese Academy of Sciences, Qingdao 266071, China
| | - Lixia Shang
- CAS Key Laboratory of Marine Ecology and Environmental Sciences, Institute of Oceanology, Chinese Academy of Sciences, 7 Nanhai Road, Qingdao 266071, China; Laboratory for Marine Ecology and Environmental Science, Qingdao National Laboratory for Marine Science and Technology, Qingdao 266237, China; Center for Ocean Mega-Science, Chinese Academy of Sciences, Qingdao 266071, China
| | - Christopher J Gobler
- School of Marine and Atmospheric Sciences, Stony Brook University, Stony Brook, NY 11790, USA
| | - Ying Zhong Tang
- CAS Key Laboratory of Marine Ecology and Environmental Sciences, Institute of Oceanology, Chinese Academy of Sciences, 7 Nanhai Road, Qingdao 266071, China; Laboratory for Marine Ecology and Environmental Science, Qingdao National Laboratory for Marine Science and Technology, Qingdao 266237, China; Center for Ocean Mega-Science, Chinese Academy of Sciences, Qingdao 266071, China.
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16
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Song W, Zhang T, Dong J, Luo X, Bourland WA, Wang Y. Taxonomy and Molecular Phylogeny of Two New Urostylid Ciliates (Protozoa: Ciliophora) From Chinese Wetlands and Establishment of a New Genus. Front Microbiol 2021; 12:707954. [PMID: 34394057 PMCID: PMC8361796 DOI: 10.3389/fmicb.2021.707954] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2021] [Accepted: 07/02/2021] [Indexed: 11/16/2022] Open
Abstract
Hypotrich ciliates with evolutionary novelties are continually being discovered, challenging the current taxonomic system and attracting increased attention. In the present work, two new urostylid ciliates, Heterobakuella bergeri gen. nov., sp. nov. and Anteholosticha perezuzae sp. nov., isolated from Chinese wetland samples, were identified based on morphology and 18S rRNA gene sequences. Heterobakuella gen. nov. is defined by three frontal cirri, single buccal cirrus, one parabuccal cirrus, midventral complex composed of cirral pairs and one cirral row, one left and two right marginal cirral rows, transverse and pretransverse cirri present, caudal and frontoterminal cirri absent. Heterobakuella can be easily distinguished from the morphologically most similar genus, Apobakuella, mainly by the single buccal cirrus (vs. one buccal cirral row) and one parabuccal cirrus (vs. several parabuccal cirral rows originated from different anlagen). Phylogenetic analyses show that H. bergeri branches within the clade formed by Bergeriella ovata, Monocoronella carnea, Anteholosticha gracilis, and Neourostylopsis spp., rather than the clade represented by Apobakuella. The other species, A. perezuzae, is mainly characterized by a distinctly slender body shape with an average length:width ratio about 7, distinctively shaped biconcave and greenish cortical granules, as well as one or two pretransverse cirri. Phylogenetic analyses indicate the genus Anteholosticha is non-monophyletic.
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Affiliation(s)
- Wenya Song
- Laboratory of Protozoological Biodiversity and Evolution in Wetland, College of Life Sciences, Shaanxi Normal University, Xi’an, China
- Institute of Evolution and Marine Biodiversity, Ocean University of China, Qingdao, China
| | - Tengyue Zhang
- Institute of Evolution and Marine Biodiversity, Ocean University of China, Qingdao, China
- Department of Zoology, Comenius University in Bratislava, Bratislava, Slovakia
| | - Jingyi Dong
- Institute of Evolution and Marine Biodiversity, Ocean University of China, Qingdao, China
| | - Xiaotian Luo
- Key Laboratory of Aquatic Biodiversity and Conservation of Chinese Academy of Sciences, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, China
| | - William A. Bourland
- Department of Zoology, Faculty of Science, Charles University, Prague, Czechia
| | - Yurui Wang
- Laboratory of Protozoological Biodiversity and Evolution in Wetland, College of Life Sciences, Shaanxi Normal University, Xi’an, China
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17
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Wang C, Gao Y, Lu B, Chi Y, Zhang T, El-Serehy HA, Al-Farraj SA, Li L, Song W, Gao F. Large-scale phylogenomic analysis provides new insights into the phylogeny of the class Oligohymenophorea (Protista, Ciliophora) with establishment of a new subclass Urocentria nov. subcl. Mol Phylogenet Evol 2021; 159:107112. [PMID: 33609708 DOI: 10.1016/j.ympev.2021.107112] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2020] [Revised: 01/28/2021] [Accepted: 02/08/2021] [Indexed: 02/06/2023]
Abstract
The class Oligohymenophorea is one of the most diverse assemblage of ciliated protists, which are particularly important in fundamental biological studies including understanding the evolutionary relationships among the lineages. Phylogenetic relationships within the class remain largely elusive, especially within the subclass Peniculia, which contains the long-standing problematic taxa Urocentrum and Paranassula. In the present study, we sequenced the genomes and/or transcriptomes of six non-culturable oligohymenophoreans using single-cell sequencing techniques. Phylogenomic analysis was performed based on expanded taxon sampling of 85 taxa, including 157 nuclear genes encoding 36,953 amino acids. The results indicate that: (1) urocentrids form an independent branch that is sister to the clade formed by Scuticociliatia and Hymenostomatia, which, together with the morphological data, supports the establishment of a new subclass, Urocentria n. subcl., within Oligohymenophorea; (2) phylogenomic analysis and ortholog comparison reveal a close relationship between Paranassula and peniculines, providing corroborative evidence for removing Paranassula from Nassulida and elevating it as an order, Paranassulida, within the subclass Peniculia; (3) based on the phylogenomic analyses and morphological data, we hypothesize that Peritrichia is the earliest diverging clade within Oligohymenophorea while Scuticociliatia and Hymenostomatia share the most common ancestor, followed successively by Urocentria and Peniculia. In addition, stop codon analyses indicate that oligohymenophoreans widely use UGA as the stop codon, while UAR are reassigned to glutamate (peritrichs) or glutamine (others), supporting the evolutionary hypothesis.
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Affiliation(s)
- Chundi Wang
- Laboratory of Marine Protozoan Biodiversity & Evolution, Ocean College, Shandong University, Weihai 264209, China; Institute of Evolution & Marine Biodiversity and College of Fisheries, Ocean University of China, Qingdao 266003, China
| | - Yunyi Gao
- Institute of Evolution & Marine Biodiversity and College of Fisheries, Ocean University of China, Qingdao 266003, China
| | - Borong Lu
- Institute of Evolution & Marine Biodiversity and College of Fisheries, Ocean University of China, Qingdao 266003, China
| | - Yong Chi
- Institute of Evolution & Marine Biodiversity and College of Fisheries, Ocean University of China, Qingdao 266003, China
| | - Tengteng Zhang
- Institute of Evolution & Marine Biodiversity and College of Fisheries, Ocean University of China, Qingdao 266003, China
| | - Hamed A El-Serehy
- Zoology Department, College of Science, King Saud University, Riyadh 11451, Saudi Arabia
| | - Saleh A Al-Farraj
- Zoology Department, College of Science, King Saud University, Riyadh 11451, Saudi Arabia
| | - Lifang Li
- Laboratory of Marine Protozoan Biodiversity & Evolution, Ocean College, Shandong University, Weihai 264209, China
| | - Weibo Song
- Laboratory of Marine Protozoan Biodiversity & Evolution, Ocean College, Shandong University, Weihai 264209, China; Institute of Evolution & Marine Biodiversity and College of Fisheries, Ocean University of China, Qingdao 266003, China; Laboratory for Marine Biology and Biotechnology, Qingdao National Laboratory for Marine Science and Technology, Qingdao 266237, China
| | - Feng Gao
- Institute of Evolution & Marine Biodiversity and College of Fisheries, Ocean University of China, Qingdao 266003, China; Laboratory for Marine Biology and Biotechnology, Qingdao National Laboratory for Marine Science and Technology, Qingdao 266237, China.
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18
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Fan X, Yao S, Luo X, Dong T, Xu Y, Chen L, Bourland W, Zhao Y, Huang J. Some morphologically distinguishable hypotrich ciliates share identical 18S rRNA gene sequences – taxonomic insights from a case study on Oxytricha species (Protista, Ciliophora). Zool J Linn Soc 2021. [DOI: 10.1093/zoolinnean/zlaa145] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022]
Abstract
Abstract
Modern taxonomic studies of ciliated protozoa require both morphological and molecular data. One dilemma is how to distinguish morphologically similar species with few nucleotide differences in the widely used marker, the 18S rRNA gene. In the present study, two Oxytricha species were morphologically documented using light and electron microscopy. The mitochondrial cytochrome c oxidase subunit I (COI) gene and a fragment of the rRNA gene covering the 18S-ITS1-5.8S-ITS2-28S rRNA gene regions were sequenced. Phylogenetic analyses of all available Oxytricha granulifera-related populations were performed to reveal the internal relationships of this group. We described a new species, Oxytricha atypica sp. nov., distinguished from its congeners by having seven postoral ventral cirri resulting from the additional fragmentation of anlage V during ontogenesis. Although their 18S rRNA genes differ by only one nucleotide, divergence of the COI gene is as high as 11.8% between O. atypica and the closely related species, O. granulifera. All but one of the COI nucleotide substitutions were synonymous. We documented the highly conserved nature of the 18S rRNA gene in the morphospecies of Oxytricha. Based on these findings, we speculate that O. granulifera contains cryptic species or morphospecies needing further characterization, and new insights for the taxonomy of hypotrich ciliates are also discussed.
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Affiliation(s)
- Xinpeng Fan
- School of Life Sciences, East China Normal University, Shanghai, China
| | - Shunli Yao
- School of Life Sciences, East China Normal University, Shanghai, China
| | - Xiaotian Luo
- Key Laboratory of Aquatic Biodiversity and Conservation of the Chinese Academy of Sciences, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, China
| | - Tianyao Dong
- School of Life Sciences, East China Normal University, Shanghai, China
| | - Yuan Xu
- State Key Laboratory of Estuarine and Coastal Research, East China Normal University, Shanghai, China
| | - Lingyun Chen
- College of Life Science, Northwest Normal University, Lanzhou, China
| | - William Bourland
- Department of Biological Sciences, Boise State University, Boise, ID, USA
| | - Yan Zhao
- College of Life Sciences, Capital Normal University, Beijing, China
| | - Jie Huang
- Key Laboratory of Aquatic Biodiversity and Conservation of the Chinese Academy of Sciences, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, China
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19
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Further insights into the phylogeny of peniculid ciliates (Ciliophora, Oligohymenophorea) based on multigene data. Mol Phylogenet Evol 2020; 154:107003. [PMID: 33137410 DOI: 10.1016/j.ympev.2020.107003] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2020] [Revised: 10/25/2020] [Accepted: 10/27/2020] [Indexed: 12/31/2022]
Abstract
Peniculids comprise a large order of ciliated protists in Class Oligohymenophorea having many unresolved evolutionary relationships. Herein, we report 27 new sequences, including 18S rRNA, ITS1-5.8S- ITS2 rRNA, 28S rRNA and the mitochondrial cox1 genes of eight peniculids. We conducted phylogenetic analyses based on each these markers and on a four-gene concatenated data set (18S rRNA, ITS1-5.8S- ITS2 rRNA, 28S rRNA, and cox1 gene). The main findings are: 1) subclass Peniculia and family Parameciidae are monophyletic, with genus Frontonia remaining non-monophyletic; 2) Urocentrids have traditionally been regarded as a family, multi-gene analyses support the rank of Urocentrida and consistently recovers this order as sister to Peniculida, and Urocentrida and Peniculida comprise subclass Peniculia in agreement with Lynn's (2008) classification; 3) discrepancies between multiple-gene phylogenies, and conflicts with morphologic data regarding genus Frontonia necessitate expansion and revision of species diagnoses and we propose consideration of Group III of Frontonia (including F. didieri, F. ocularis, F. anatolica, F. pusilla and F. elegans) as incertae sedis in Peniculida; 4) multi-gene analyses of Parameciidae support five previously established subgenera. Paramecium buetschlii is placed in subgenus Chloroparamecium, and P. chlorelligerum into subgenus Viridoparamecium.
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20
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Iniesto M, Moreira D, Reboul G, Deschamps P, Benzerara K, Bertolino P, Saghaï A, Tavera R, López-García P. Core microbial communities of lacustrine microbialites sampled along an alkalinity gradient. Environ Microbiol 2020; 23:51-68. [PMID: 32985763 DOI: 10.1111/1462-2920.15252] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2020] [Revised: 08/26/2020] [Accepted: 09/23/2020] [Indexed: 11/28/2022]
Abstract
Microbialites are usually carbonate-rich sedimentary rocks formed by the interplay of phylogenetically and metabolically complex microbial communities with their physicochemical environment. Yet, the biotic and abiotic determinants of microbialite formation remain poorly constrained. Here, we analysed the structure of prokaryotic and eukaryotic communities associated with microbialites occurring in several crater lakes of the Trans-Mexican volcanic belt along an alkalinity gradient. Microbialite size and community structure correlated with lake physicochemical parameters, notably alkalinity. Although microbial community composition varied across lake microbialites, major taxa-associated functions appeared quite stable with both, oxygenic and anoxygenic photosynthesis and, to less extent, sulphate reduction, as major putative carbonatogenic processes. Despite interlake microbialite community differences, we identified a microbial core of 247 operational taxonomic units conserved across lake microbialites, suggesting a prominent ecological role in microbialite formation. This core mostly encompassed Cyanobacteria and their typical associated taxa (Bacteroidetes, Planctomycetes) and diverse anoxygenic photosynthetic bacteria, notably Chloroflexi, Alphaproteobacteria (Rhodobacteriales, Rhodospirilalles), Gammaproteobacteria (Chromatiaceae) and minor proportions of Chlorobi. The conserved core represented up to 40% (relative abundance) of the total community in lakes Alchichica and Atexcac, displaying the highest alkalinities and the most conspicuous microbialites. Core microbialite communities associated with carbonatogenesis might be relevant for inorganic carbon sequestration purposes.
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Affiliation(s)
- Miguel Iniesto
- Unité d'Ecologie Systématique et Evolution, CNRS, Université Paris-Saclay, AgroParisTech, Orsay, France
| | - David Moreira
- Unité d'Ecologie Systématique et Evolution, CNRS, Université Paris-Saclay, AgroParisTech, Orsay, France
| | - Guillaume Reboul
- Unité d'Ecologie Systématique et Evolution, CNRS, Université Paris-Saclay, AgroParisTech, Orsay, France
| | - Philippe Deschamps
- Unité d'Ecologie Systématique et Evolution, CNRS, Université Paris-Saclay, AgroParisTech, Orsay, France
| | - Karim Benzerara
- Institut de Minéralogie, de Physique des Matériaux et de Cosmochimie, CNRS, Muséum National d'Histoire Naturelle, Sorbonne Université, Paris, France
| | - Paola Bertolino
- Unité d'Ecologie Systématique et Evolution, CNRS, Université Paris-Saclay, AgroParisTech, Orsay, France
| | - Aurélien Saghaï
- Unité d'Ecologie Systématique et Evolution, CNRS, Université Paris-Saclay, AgroParisTech, Orsay, France.,Department of Forest Mycology and Plant Pathology, Swedish University of Agricultural Sciences, Uppsala, Sweden
| | - Rosaluz Tavera
- Departamento de Ecología y Recursos Naturales, Universidad Nacional Autónoma de México, DF Mexico, Mexico
| | - Purificación López-García
- Unité d'Ecologie Systématique et Evolution, CNRS, Université Paris-Saclay, AgroParisTech, Orsay, France
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21
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New contributions to the phylogeny of the ciliate class Heterotrichea (Protista, Ciliophora): analyses at family-genus level and new evolutionary hypotheses. SCIENCE CHINA-LIFE SCIENCES 2020; 64:606-620. [PMID: 33068287 DOI: 10.1007/s11427-020-1817-5] [Citation(s) in RCA: 26] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/16/2020] [Accepted: 09/06/2020] [Indexed: 01/15/2023]
Abstract
Heterotrichous ciliates play an important role in aquatic ecosystem energy flow processes and many are model organisms for research in cytology, regenerative biology, and toxicology. In the present study, we combine both morphological and molecular data to infer phylogenetic relationships at family-genus level and propose new evolutionary hypotheses for the class Heterotrichea. The main results include: (1) 96 new ribosomal DNA sequences from 36 populations, representing eight families and 13 genera, including three poorly annotated genera, Folliculinopsis, Ampullofolliculina and Linostomella; (2) the earliest-branching families are Spirostomidae in single-gene trees and Peritromidae in the concatenated tree, but the family Peritromidae probably represents the basal lineage based on its possession of many "primitive" morphological characters; (3) some findings in molecular trees are not supported by morphological evidence, such as the family Blepharismidae is one of the most recent branches and the relationship between Fabreidae and Folliculinidae is very close; (4) the systematic positions of Condylostomatidae, Climacostomidae, and Gruberiidae remain uncertain based either on morphological or molecular data; and (5) the monophyly of each genus included in the present study is supported by the molecular phylogenetic trees, except for Blepharisma in the SSU rDNA tree and Folliculina in the ITS1-5.8S-ITS2 tree.
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22
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Chi Y, Li Y, Zhang Q, Ma M, Warren A, Chen X, Song W. New contributions to two ciliate genera (Ciliophora, Heterotrichea) based on morphological and molecular analyses, with description of a new Gruberia species. BMC Microbiol 2020; 20:297. [PMID: 33008292 PMCID: PMC7531149 DOI: 10.1186/s12866-020-01879-4] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2020] [Accepted: 06/25/2020] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Heterotrichous ciliates are common members of microeukaryote communities which play important roles in both the transfer of material and the flow of energy in aquatic food webs. This group has been known for over two centuries due to their large body size and cosmopolitan distribution. Nevertheless, species identification and phylogenetic relationships of heterotrichs remain challenging due to the lack of accurate morphological information and insufficient molecular data. RESULTS The morphology and phylogeny of two heterotrichous ciliates, namely Gruberia foissneri spec. nov. and Linostomella vorticella (Ehrenberg, 1833) Aescht in Foissner et al., 1999, were studied using rigorous methods (living morphology, stained preparations, and small subunit rDNA sequence data). Gruberia foissneri spec. nov. is morphologically very similar to G. uninucleata Kahl, 1932, however, it can be distinguished from the latter by having more ciliary rows (about 32 vs. about 20) and macronuclear shape (sausage-shaped vs. ellipsoid). Based on a combination of previous and present studies, an improved diagnosis of L. vorticella is supplied and several taxonomic anomalies are clarified. In addition, phylogenetic analyses based on SSU rDNA sequence data support the generic assignment of these two species. CONCLUSIONS Modern ciliate taxonomy should be performed by means of detailed living observation, stained preparations and molecular information. For those species that have been reported in previous studies, it is necessary to provide as much useful information as possible using state-of-the-art methods in order to resolve taxonomic anomalies.
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Affiliation(s)
- Yong Chi
- Institute of Evolution and Marine Biodiversity, and College of Fisheries, Ocean University of China, Qingdao, 266003, China
| | - Yuqing Li
- Institute of Evolution and Marine Biodiversity, and College of Fisheries, Ocean University of China, Qingdao, 266003, China
| | - Qianqian Zhang
- Yantai Institute of Coastal Zone Research, Chinese Academy of Sciences, Yantai, 264003, China.,Center for Ocean Mega-Science, Chinese Academy of Sciences, 7 Nanhai Road, Qingdao, 266071, China
| | - Mingzhen Ma
- Institute of Evolution and Marine Biodiversity, and College of Fisheries, Ocean University of China, Qingdao, 266003, China
| | - Alan Warren
- Department of Life Sciences, Natural History Museum, London, SW7 5BD, UK
| | - Xiangrui Chen
- School of Marine Sciences, Ningbo University, Ningbo, 315211, China.
| | - Weibo Song
- Institute of Evolution and Marine Biodiversity, and College of Fisheries, Ocean University of China, Qingdao, 266003, China.
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23
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Does Intraspecific Variation in rDNA Copy Number Affect Analysis of Microbial Communities? Trends Microbiol 2020; 29:19-27. [PMID: 32593503 DOI: 10.1016/j.tim.2020.05.019] [Citation(s) in RCA: 50] [Impact Index Per Article: 12.5] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2020] [Revised: 05/23/2020] [Accepted: 05/28/2020] [Indexed: 01/01/2023]
Abstract
Amplicon sequencing of partial regions of the ribosomal RNA loci (rDNA) is widely used to profile microbial communities. However, the rDNA is dynamic and can exhibit substantial interspecific and intraspecific variation in copy number in prokaryotes and, especially, in microbial eukaryotes. As change in rDNA copy number is a common response to environmental change, rDNA copy number is not necessarily a property of a species. Variation in rDNA copy number, especially the capacity for large intraspecific changes driven by external cues, complicates analyses of rDNA amplicon sequence data. We highlight the need to (i) interpret amplicon sequence data in light of possible interspecific and intraspecific variation, and (ii) examine the potential plasticity in rDNA copy number as an important ecological factor to better understand how microbial communities are structured in heterogeneous environments.
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24
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Armbrecht L, Herrando-Pérez S, Eisenhofer R, Hallegraeff GM, Bolch CJS, Cooper A. An optimized method for the extraction of ancient eukaryote DNA from marine sediments. Mol Ecol Resour 2020; 20:906-919. [PMID: 32277584 DOI: 10.1111/1755-0998.13162] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2019] [Revised: 03/17/2020] [Accepted: 03/26/2020] [Indexed: 12/19/2022]
Abstract
Marine sedimentary ancient DNA (sedaDNA) provides a powerful means to reconstruct marine palaeo-communities across the food web. However, currently there are few optimized sedaDNA extraction protocols available to maximize the yield of small DNA fragments typical of ancient DNA (aDNA) across a broad diversity of eukaryotes. We compared seven combinations of sedaDNA extraction treatments and sequencing library preparations using marine sediments collected at a water depth of 104 m off Maria Island, Tasmania, in 2018. These seven methods contrasted frozen versus refrigerated sediment, bead-beating induced cell lysis versus ethylenediaminetetraacetic acid (EDTA) incubation, DNA binding in silica spin columns versus in silica-solution, diluted versus undiluted DNA in shotgun library preparations to test potential inhibition issues during amplification steps, and size-selection of low molecular-weight (LMW) DNA to increase the extraction efficiency of sedaDNA. Maximum efficiency was obtained from frozen sediments subjected to a combination of EDTA incubation and bead-beating, DNA binding in silica-solution, and undiluted DNA in shotgun libraries, across 45 marine eukaryotic taxa. We present an optimized extraction protocol integrating these steps, with an optional post-library LMW size-selection step to retain DNA fragments of ≤500 base pairs. We also describe a stringent bioinformatic filtering approach for metagenomic data and provide a comprehensive list of contaminants as a reference for future sedaDNA studies. The new extraction and data-processing protocol should improve quantitative paleo-monitoring of eukaryotes from marine sediments, as well as other studies relying on the detection of highly fragmented and degraded eukaryote DNA in sediments.
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Affiliation(s)
- Linda Armbrecht
- School of Biological Sciences, Faculty of Sciences, Australian Centre for Ancient DNA, The University of Adelaide, Adelaide, SA, Australia
| | - Salvador Herrando-Pérez
- School of Biological Sciences, Faculty of Sciences, Australian Centre for Ancient DNA, The University of Adelaide, Adelaide, SA, Australia
| | - Raphael Eisenhofer
- School of Biological Sciences, Faculty of Sciences, Australian Centre for Ancient DNA, The University of Adelaide, Adelaide, SA, Australia
| | - Gustaaf M Hallegraeff
- Institute for Marine and Antarctic Studies, University of Tasmania, Hobart, Tas., Australia
| | - Christopher J S Bolch
- Institute for Marine and Antarctic Studies, University of Tasmania, Launceston, Tas., Australia
| | - Alan Cooper
- South Australian Museum, Adelaide, SA, Australia
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25
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Salmaso N, Boscaini A, Pindo M. Unraveling the Diversity of Eukaryotic Microplankton in a Large and Deep Perialpine Lake Using a High Throughput Sequencing Approach. Front Microbiol 2020; 11:789. [PMID: 32457713 PMCID: PMC7221148 DOI: 10.3389/fmicb.2020.00789] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2019] [Accepted: 04/02/2020] [Indexed: 11/28/2022] Open
Abstract
The structure of microbial communities, microalgae, heterotrophic protozoa and fungi contributes to characterize food webs and productivity and, from an anthropogenic point of view, the qualitative characteristics of water bodies. Traditionally, in freshwater environments many investigations have been directed to the study of pelagic microalgae (“phytoplankton”) and periphyton (i.e., photosynthetic and mixotrophic protists) through the use of light microscopy (LM). While the number of studies on bacterioplankton communities have shown a substantial increase after the advent of high-throughput sequencing (HTS) approaches, the study of the composition, structure, and spatio-temporal patterns of microbial eukaryotes in freshwater environments was much less widespread. Moreover, the understanding of the correspondence between the relative phytoplankton abundances estimated by HTS and LM is still incomplete. Taking into account these limitations, this study examined the biodiversity and seasonality of the community of eukaryotic microplankton in the epilimnetic layer of a large and deep perialpine lake (Lake Garda) using HTS. The analyses were carried out at monthly frequency during 2014 and 2015. The results highlighted the existence of a rich and well diversified community and the presence of numerous phytoplankton taxa that were never identified by LM in previous investigations. Furthermore, the relative abundances of phytoplankton estimated by HTS and LM showed a significant relationship at different taxonomic ranks. In the 2 years of investigation, the temporal development of the whole micro-eukaryotic community showed a clear non-random and comparable distribution pattern, with the main taxonomic groups coherently distributed in the individual seasons. In perspective, the results obtained in this study highlight the importance of HTS approaches in assessing biodiversity and the relative importance of the main protist groups along environmental gradients, including those caused by anthropogenic impacts (e.g., eutrophication and climate change).
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Affiliation(s)
- Nico Salmaso
- Research and Innovation Centre, Fondazione Edmund Mach, San Michele all'Adige, Italy
| | - Adriano Boscaini
- Research and Innovation Centre, Fondazione Edmund Mach, San Michele all'Adige, Italy
| | - Massimo Pindo
- Research and Innovation Centre, Fondazione Edmund Mach, San Michele all'Adige, Italy
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26
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Two new scuticociliates from southern China: Uronema apomarinum sp. nov. and Homalogastra parasetosa sp. nov., with improved diagnoses of the genus Homalogastra and its type species Homalogastra setosa (Ciliophora, Oligohymenophorea). Int J Syst Evol Microbiol 2020; 70:2405-2419. [DOI: 10.1099/ijsem.0.004046] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
The morphology of two new scuticociliates, Uronema apomarinum sp. nov. and Homalogastra parasetosa sp. nov., isolated from a mangrove wetland in Shenzhen, PR China, was studied using live observation and the protargol impregnation method. Uronema apomarinum is characterized by a body size of about 20–35×10–15 µm in vivo, a partly two-rowed membranelle 1, and 12 or 13 somatic kineties. Homalogastra parasetosa is distinguished by a membranelle 1 comprising two longitudinal rows of basal bodies. Three Homalogastra setosa populations are suggested as subjective synonyms of the new species. Improved diagnoses of the genus Homalogastra Kahl, 1926 and its type species Homalogastra setosa Kahl, 1926 are provided. Results of phylogenetic analyses based on 18S rRNA gene and ITS1-5.8S–ITS2 region sequences indicate that U. apomarinum is most closely related to U. marinum, while the closest relative of H. parasetosa is H. setosa.
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27
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Ruggiero A, Grattepanche JD, Weiner AKM, Katz LA. High Diversity of Testate Amoebae (Amoebozoa, Arcellinida) Detected by HTS Analyses in a New England Fen using Newly Designed Taxon-specific Primers. J Eukaryot Microbiol 2020; 67:450-462. [PMID: 32145128 DOI: 10.1111/jeu.12794] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2019] [Revised: 02/20/2020] [Accepted: 02/25/2020] [Indexed: 01/01/2023]
Abstract
Testate (shell-building) amoebae, such as the Arcellinida (Amoebozoa), are useful bioindicators for climate change. Though past work has relied on morphological analyses to characterize Arcellinida diversity, genetic analyses revealed the presence of multiple cryptic species underlying morphospecies. Here, we design and deploy Arcellinida-specific primers for the SSU-rDNA gene to assess the community composition on the molecular level in a pilot study of two samplings from a New England fen: (1) 36-cm horizontal transects and vertical cores; and (2) 26-m horizontal transects fractioned into four size classes (2-10, 10-35, 35-100, and 100-300 μm). Analyses of these data show the following: (1) a considerable genetic diversity within Arcellinida, much of which comes from morphospecies lacking sequences on GenBank; (2) communities characterized by DNA (i.e. active + quiescent) are distinct from those characterized by RNA (i.e. active, indicator of biomass); (3) active communities on the surface tend to be more similar to one another than to core communities, despite considerable heterogeneity; and (4) analyses of communities fractioned by size find some lineages (OTUs) that are abundant in disjunct size categories, suggesting the possibility of life-history stages. Together, these data demonstrate the potential of these primers to elucidate the diversity of Arcellinida communities in diverse habitats.
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Affiliation(s)
- Alistaire Ruggiero
- Department of Biological Science, Smith College, 44 College Lane, Northampton, Massachusetts, 01063
| | - Jean-David Grattepanche
- Department of Biological Science, Smith College, 44 College Lane, Northampton, Massachusetts, 01063
| | - Agnes K M Weiner
- Department of Biological Science, Smith College, 44 College Lane, Northampton, Massachusetts, 01063
| | - Laura A Katz
- Department of Biological Science, Smith College, 44 College Lane, Northampton, Massachusetts, 01063.,Program in Organismic and Evolutionary Biology, University of Massachusetts Amherst, Amherst, Massachusetts, 01003
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28
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Wang R, Song W, Bai Y, Warren A, Li L, Hu X. Morphological redescriptions and neotypification of two poorly known tintinnine ciliates (Alveolata, Ciliophora, Tintinnina), with a phylogenetic investigation based on SSU rRNA gene sequences. Int J Syst Evol Microbiol 2020; 70:2515-2530. [PMID: 32118526 DOI: 10.1099/ijsem.0.004065] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Two poorly known tintinnine ciliates collected from the coastal waters of PR China, viz., Codonellopsis mobilis Wang, 1936 and Tintinnopsis chinglanensis Nie & Ch'eng, 1947, were redescribed and neotypified using live observation, protargol staining and SSU rRNA gene sequencing. Ciliature information and SSU rRNA gene sequence data of both species were revealed for the first time and improved diagnoses were given based on the original descriptions and data from the present study. Further phylogenetic analyses inferred from SSU rRNA gene sequences and morphological data suggested that the genus Tintinnopsis is polyphyletic and that the genus Codonellopsis is non-monophyletic. The approximately unbiased test, however, does not reject the possibility that Codonellopsis is monophyletic.
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Affiliation(s)
- Rui Wang
- Institute of Evolution and Marine Biodiversity; Key Laboratory of Mariculture, Ministry of Education, Ocean University of China (OUC), Qingdao 266003, PR China
| | - Wen Song
- Marine College, Shandong University, Weihai 264209, PR China
| | - Yang Bai
- Institute of Evolution and Marine Biodiversity; Key Laboratory of Mariculture, Ministry of Education, Ocean University of China (OUC), Qingdao 266003, PR China
| | - Alan Warren
- Department of Life Sciences, Natural History Museum, London SW7 5BD, UK
| | - Lifang Li
- Marine College, Shandong University, Weihai 264209, PR China
| | - Xiaozhong Hu
- Institute of Evolution and Marine Biodiversity; Key Laboratory of Mariculture, Ministry of Education, Ocean University of China (OUC), Qingdao 266003, PR China
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29
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Wang Y, Jiang Y, Liu Y, Li Y, Katz LA, Gao F, Yan Y. Comparative Studies on the Polymorphism and Copy Number Variation of mtSSU rDNA in Ciliates (Protista, Ciliophora): Implications for Phylogenetic, Environmental, and Ecological Research. Microorganisms 2020; 8:microorganisms8030316. [PMID: 32106521 PMCID: PMC7142639 DOI: 10.3390/microorganisms8030316] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2020] [Revised: 02/20/2020] [Accepted: 02/21/2020] [Indexed: 01/21/2023] Open
Abstract
While nuclear small subunit ribosomal DNA (nSSU rDNA) is the most commonly-used gene marker in studying phylogeny, ecology, abundance, and biodiversity of microbial eukaryotes, mitochondrial small subunit ribosomal DNA (mtSSU rDNA) provides an alternative. Recently, both copy number variation and sequence variation of nSSU rDNA have been demonstrated for diverse organisms, which can contribute to misinterpretation of microbiome data. Given this, we explore patterns for mtSSU rDNA among 13 selected ciliates (representing five classes), a major component of microbial eukaryotes, estimating copy number and sequence variation and comparing to that of nSSU rDNA. Our study reveals: (1) mtSSU rDNA copy number variation is substantially lower than that for nSSU rDNA; (2) mtSSU rDNA copy number ranges from 1.0 × 104 to 8.1 × 105; (3) a most common sequence of mtSSU rDNA is also found in each cell; (4) the sequence variation of mtSSU rDNA are mainly indels in poly A/T regions, and only half of species have sequence variation, which is fewer than that for nSSU rDNA; and (5) the polymorphisms between haplotypes of mtSSU rDNA would not influence the phylogenetic topology. Together, these data provide more insights into mtSSU rDNA as a powerful marker especially for microbial ecology studies.
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Affiliation(s)
- Yurui Wang
- Institute of Evolution & Marine Biodiversity, Ocean University of China, Qingdao 266003, China; (Y.W.); (Y.J.); (Y.L.); (Y.L.); (F.G.)
- Key Laboratory of Mariculture, Ministry of Education, Ocean University of China, Qingdao 266003, China
| | - Yaohan Jiang
- Institute of Evolution & Marine Biodiversity, Ocean University of China, Qingdao 266003, China; (Y.W.); (Y.J.); (Y.L.); (Y.L.); (F.G.)
- Key Laboratory of Mariculture, Ministry of Education, Ocean University of China, Qingdao 266003, China
| | - Yongqiang Liu
- Institute of Evolution & Marine Biodiversity, Ocean University of China, Qingdao 266003, China; (Y.W.); (Y.J.); (Y.L.); (Y.L.); (F.G.)
- Key Laboratory of Mariculture, Ministry of Education, Ocean University of China, Qingdao 266003, China
| | - Yuan Li
- Institute of Evolution & Marine Biodiversity, Ocean University of China, Qingdao 266003, China; (Y.W.); (Y.J.); (Y.L.); (Y.L.); (F.G.)
- Key Laboratory of Mariculture, Ministry of Education, Ocean University of China, Qingdao 266003, China
| | - Laura A. Katz
- Department of Biological Sciences, Smith College, Northampton, MA 01063, USA;
| | - Feng Gao
- Institute of Evolution & Marine Biodiversity, Ocean University of China, Qingdao 266003, China; (Y.W.); (Y.J.); (Y.L.); (Y.L.); (F.G.)
- Key Laboratory of Mariculture, Ministry of Education, Ocean University of China, Qingdao 266003, China
| | - Ying Yan
- Institute of Evolution & Marine Biodiversity, Ocean University of China, Qingdao 266003, China; (Y.W.); (Y.J.); (Y.L.); (Y.L.); (F.G.)
- Key Laboratory of Mariculture, Ministry of Education, Ocean University of China, Qingdao 266003, China
- Department of Biological Sciences, Smith College, Northampton, MA 01063, USA;
- Correspondence:
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30
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Nguyen LN, Commault AS, Kahlke T, Ralph PJ, Semblante GU, Johir MAH, Nghiem LD. Genome sequencing as a new window into the microbial community of membrane bioreactors - A critical review. THE SCIENCE OF THE TOTAL ENVIRONMENT 2020; 704:135279. [PMID: 31791792 DOI: 10.1016/j.scitotenv.2019.135279] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/15/2019] [Revised: 10/27/2019] [Accepted: 10/28/2019] [Indexed: 06/10/2023]
Abstract
Recent developed sequencing techniques have resulted in a new and unprecedented way to study biological wastewater treatment, in which most organisms are uncultivable. This review provides (i) an insight on state-of-the-art sequencing techniques and their limitations; (ii) a critical assessment of the microbial community in biological reactor and biofouling layer in a membrane bioreactor (MBR). The data from high-throughput sequencing has been used to infer microbial growth conditions and metabolisms of microorganisms present in MBRs at the time of sampling. These data shed new insight to two fundamental questions about a microbial community in the MBR process namely the microbial composition (who are they?) and the functions of each specific microbial assemblage (what are their function?). The results to date also highlight the complexity of the microbial community growing on MBRs. Environmental conditions are dynamic and diverse, and can influence the diversity and structural dynamics of any given microbial community for wastewater treatment. The benefits of understanding the structure of microbial communities on three major aspects of the MBR process (i.e. nutrient removal, biofouling control, and micropollutant removal) were symmetrically delineated. This review also indicates that the deployment of microbial community analysis for a practical engineering context, in terms of process design and system optimization, can be further realized.
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Affiliation(s)
- Luong N Nguyen
- Centre for Technology in Water and Wastewater, School of Civil and Environmental Engineering, University of Technology Sydney, NSW 2007, Australia.
| | - Audrey S Commault
- Climate Change Cluster (C3), University of Technology Sydney, NSW 2007, Australia
| | - Tim Kahlke
- Climate Change Cluster (C3), University of Technology Sydney, NSW 2007, Australia
| | - Peter J Ralph
- Climate Change Cluster (C3), University of Technology Sydney, NSW 2007, Australia
| | - Galilee U Semblante
- Technical Services, Western Sydney University, Kingswood, NSW 2747, Australia
| | - Md Abu Hasan Johir
- Centre for Technology in Water and Wastewater, School of Civil and Environmental Engineering, University of Technology Sydney, NSW 2007, Australia
| | - Long D Nghiem
- Centre for Technology in Water and Wastewater, School of Civil and Environmental Engineering, University of Technology Sydney, NSW 2007, Australia; NTT Institute of Hi-Technology, Nguyen Tat Thanh University, Ho Chi Minh City, Viet Nam
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31
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Song W, Pan B, El-Serehy HA, Al-Farraj SA, Liu W, Li L. Morphology and Molecular Phylogeny of Two Freshwater Oligotrich Ciliates (Protozoa, Ciliophora, Oligotrichia), Pelagostrombidium fallax (Zacharias, 1895) Krainer, 1991 and Limnostrombidium viride (Stein, 1867) Krainer, 1995, with Brief Notes on Stomatogenesis. J Eukaryot Microbiol 2019; 67:232-244. [PMID: 31773849 DOI: 10.1111/jeu.12777] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2018] [Revised: 10/04/2019] [Accepted: 10/16/2019] [Indexed: 02/05/2023]
Abstract
The morphology of two oligotrich ciliates, Pelagostrombidium fallax (Zacharias, 1895) Krainer, 1991 and Limnostrombidium viride (Stein, 1867) Krainer, 1995, collected from a freshwater pond in northern China, was studied based on live observation and protargol staining. Currently, undescribed features in the girdle kinety in P. fallax are (a) sparsely spaced single argyrophilic basal bodies in the shoulder region and (b) a U-shape formed below the buccal peristome. An improved diagnosis for P. fallax is supplied, based on previous and present morphological descriptions. In addition, certain ontogenetic stages of P. fallax are reported for the first time. During division, two new embryonic bodies are successively generated de novo, the first one goes to the proter, the second one to the opisthe; the new canal derives from the old canal. The morphology of L. viride is redescribed in detail; the Chinese population is highly consistent with populations in Europe. The SSU rRNA gene of P. fallax was sequenced for the first time. Phylogenetic analyses, based on SSU rRNA gene sequence data, reveal that P. fallax and L. viride cluster with Strombidium species while the result of an AU test did not reject the possibility of monophyly of the family Pelagostrombidiidae.
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Affiliation(s)
- Wen Song
- Marine College, Shandong University, Weihai, 264209, China
| | - Bo Pan
- Institute of Evolution and Marine Biodiversity, Ocean University of China, Qingdao, 266003, China
| | - Hamed A El-Serehy
- Zoology Department, King Saud University, Riyadh, 11451, Saudi Arabia
| | - Saleh A Al-Farraj
- Zoology Department, King Saud University, Riyadh, 11451, Saudi Arabia
| | - Weiwei Liu
- Key Laboratory of Tropical Marine Bio-resources and Ecology, South China Sea Institute of Oceanology, Chinese Academy of Science, Guangzhou, 510301, China
| | - Lifang Li
- Marine College, Shandong University, Weihai, 264209, China
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32
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Evidence of Intra-individual SSU Polymorphisms in Dark-spored Myxomycetes (Amoebozoa). Protist 2019; 170:125681. [PMID: 31586669 DOI: 10.1016/j.protis.2019.125681] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2018] [Revised: 08/21/2019] [Accepted: 08/27/2019] [Indexed: 11/24/2022]
Abstract
The nuclear small subunit rRNA gene (SSU or 18S) is a marker frequently used in phylogenetic and barcoding studies in Amoebozoa, including Myxomycetes. Despite its common usage and the confirmed existence of divergent copies of ribosomal genes in other protists, the potential presence of intra-individual SSU variability in Myxomycetes has never been studied before. Here we investigated the pattern of nucleotide polymorphism in the 5' end fragment of SSU by cloning and sequencing a total of 238 variants from eight specimens, each representing a species of the dark-spored orders Stemonitidales and Physarales. After excluding singletons, a relatively low SSU intra-individual variability was found but our data indicate that this might be a widely distributed phenomenon in Myxomycetes as all samples analyzed possessed various ribotypes. To determine if the occurrence of multiple SSU variants within a single specimen has a negative effect on the circumscription of species boundaries, we conducted phylogenetic analyses that revealed that clone variation may be detrimental for inferring phylogenetic relationships among some of the specimens analyzed. Despite that intra-individual variability should be assessed in additional taxa, our results indicate that special care should be taken for species identification when working with closely related species.
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33
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Sun P, Huang L, Xu D, Warren A, Huang B, Wang Y, Wang L, Xiao W, Kong J. Integrated Space-Time Dataset Reveals High Diversity and Distinct Community Structure of Ciliates in Mesopelagic Waters of the Northern South China Sea. Front Microbiol 2019; 10:2178. [PMID: 31616397 PMCID: PMC6768975 DOI: 10.3389/fmicb.2019.02178] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2019] [Accepted: 09/05/2019] [Indexed: 12/20/2022] Open
Abstract
Little is known about diversity distribution and community structure of ciliates in mesopelagic waters, especially how they are related to spatial and temporal changes. Here, an integrative approach, combining high-throughput cDNA sequencing and quantitative protargol stain, was used to analyze ciliate communities collected temporally along a transect from coastal to oceanic regions at depths ranging from the surface to 1000 m. The mesopelagic zone exhibited comparable alpha diversity to surface water which was consistent over temporal variation, with high diversity occurring at the interface with the euphotic zone. Comparison with the northeastern and the western Pacific Ocean revealed consistency of this vertical distribution of ciliates across oceanic basins. Mesopelagic ciliates harbored distinct community structure without significant seasonal differences, with the vertical variations driven largely by members of the classes Spirotrichea and Oligohymenophorea. Operational taxonomic units (OTUs) affiliated with Scuticociliatia, Astomatida and Apostomatida, members of which are known to be bacterivorous and/or commensal/parasitic species, were more abundant in mesopelagic waters than above, implying they are an important component of food webs in the mesopelagic zone. A combination of depth, geographic distance and environment shaped the ciliate communities, with depth being the most influential factor. Phylogenetic null modeling analysis further indicated that 57.1 and 33.3% of mesopelagic community variation was governed by dispersal limitation and heterogeneous selection, respectively, probably due to the marked biochemical and physical gradients down the water column. This suggests that ciliate community structure in the mesopelagic zone is mainly controlled by stochastic processes. Collectively, this study reports mesopelagic ciliates exhibited high diversity and distinct community structure across spatiotemporal scales and informs the processes mediating ciliate assembly in the mesopelagic zone. These should be fully considered in future studies to build a more comprehensive understanding of mesopelagic microbial assemblages.
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Affiliation(s)
- Ping Sun
- Key Laboratory of the Ministry of Education for Coastal and Wetland Ecosystem, College of the Environment and Ecology, Xiamen University, Xiamen, China.,Fujian Provincial Key Laboratory for Coastal Ecology and Environmental Studies, Xiamen University, Xiamen, China
| | - Liying Huang
- Key Laboratory of the Ministry of Education for Coastal and Wetland Ecosystem, College of the Environment and Ecology, Xiamen University, Xiamen, China
| | - Dapeng Xu
- State Key Laboratory of Marine Environmental Science, Institute of Marine Microbes and Ecospheres, College of Ocean and Earth Sciences, Xiamen University, Xiamen, China
| | - Alan Warren
- Department of Life Sciences, Natural History Museum, London, United Kingdom
| | - Bangqin Huang
- Fujian Provincial Key Laboratory for Coastal Ecology and Environmental Studies, Xiamen University, Xiamen, China
| | - Ying Wang
- Key Laboratory of the Ministry of Education for Coastal and Wetland Ecosystem, College of the Environment and Ecology, Xiamen University, Xiamen, China
| | - Lei Wang
- Key Laboratory of the Ministry of Education for Coastal and Wetland Ecosystem, College of the Environment and Ecology, Xiamen University, Xiamen, China
| | - Wupeng Xiao
- Key Laboratory of the Ministry of Education for Coastal and Wetland Ecosystem, College of the Environment and Ecology, Xiamen University, Xiamen, China
| | - Jie Kong
- Key Laboratory of the Ministry of Education for Coastal and Wetland Ecosystem, College of the Environment and Ecology, Xiamen University, Xiamen, China
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34
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Xu W, Zhao Y, Pan B, Liu Y, Li Y, Bourland WA, Luo X. Morphology, Morphogenesis, and Phylogeny of
Urosoma caudata
(Ehrenberg, 1833) Berger, 1999 (Ciliophora, Hypotrichia) based on a Chinese Population. J Eukaryot Microbiol 2019; 67:76-85. [DOI: 10.1111/jeu.12756] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2019] [Revised: 07/17/2019] [Accepted: 08/11/2019] [Indexed: 11/27/2022]
Affiliation(s)
- Wenxin Xu
- Laboratory of Protozoology Institute of Evolution and Marine Biodiversity Ocean University of China Qingdao 266003 China
- Key Laboratory of Aquatic Biodiversity and Conservation of Chinese Academy of Sciences Institute of Hydrobiology Chinese Academy of Sciences Wuhan 430072 China
| | - Yan Zhao
- College of Life Sciences Capital Normal University Beijing 100048 China
| | - Bo Pan
- Laboratory of Protozoology Institute of Evolution and Marine Biodiversity Ocean University of China Qingdao 266003 China
| | - Yongqiang Liu
- Laboratory of Protozoology Institute of Evolution and Marine Biodiversity Ocean University of China Qingdao 266003 China
| | - Yuan Li
- Laboratory of Protozoology Institute of Evolution and Marine Biodiversity Ocean University of China Qingdao 266003 China
| | - William A. Bourland
- Department of Biological Sciences Boise State University Boise Idaho 83725 USA
| | - Xiaotian Luo
- Key Laboratory of Aquatic Biodiversity and Conservation of Chinese Academy of Sciences Institute of Hydrobiology Chinese Academy of Sciences Wuhan 430072 China
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35
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Wang C, Yan Y, Chen X, Al‐Farraj SA, El‐Serehy HA, Gao F. Further analyses on the evolutionary “key‐protist”
Halteria
(Protista, Ciliophora) based on transcriptomic data. ZOOL SCR 2019. [DOI: 10.1111/zsc.12380] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Affiliation(s)
- Chundi Wang
- Institute of Evolution & Marine Biodiversity Ocean University of China Qingdao China
- Key Laboratory of Mariculture (Ocean University of China) Ministry of Education Qingdao China
| | - Ying Yan
- Institute of Evolution & Marine Biodiversity Ocean University of China Qingdao China
- Key Laboratory of Mariculture (Ocean University of China) Ministry of Education Qingdao China
| | - Xiao Chen
- Institute of Evolution & Marine Biodiversity Ocean University of China Qingdao China
- Key Laboratory of Mariculture (Ocean University of China) Ministry of Education Qingdao China
- Department of Genetics and Development Columbia University Medical Center New York NY USA
| | - Saleh A. Al‐Farraj
- Zoology Department, College of Science King Saud University Riyadh Saudi Arabia
| | - Hamed A. El‐Serehy
- Zoology Department, College of Science King Saud University Riyadh Saudi Arabia
| | - Feng Gao
- Institute of Evolution & Marine Biodiversity Ocean University of China Qingdao China
- Key Laboratory of Mariculture (Ocean University of China) Ministry of Education Qingdao China
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36
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Forster D, Lentendu G, Filker S, Dubois E, Wilding TA, Stoeck T. Improving eDNA-based protist diversity assessments using networks of amplicon sequence variants. Environ Microbiol 2019; 21:4109-4124. [PMID: 31361938 DOI: 10.1111/1462-2920.14764] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2019] [Revised: 07/25/2019] [Accepted: 07/25/2019] [Indexed: 12/20/2022]
Abstract
Effective and precise grouping of highly similar sequences remains a major bottleneck in the evaluation of high-throughput sequencing datasets. Amplicon sequence variants (ASVs) offer a promising alternative that may supersede the widely used operational taxonomic units (OTUs) in environmental sequencing studies. We compared the performance of a recently developed pipeline based on the algorithm DADA2 for obtaining ASVs against a pipeline based on the algorithm SWARM for obtaining OTUs. Illumina-sequencing of 29 individual ciliate species resulted in up to 11 ASVs per species, while SWARM produced up to 19 OTUs per species. To improve the congruency between species diversity and molecular diversity, we applied sequence similarity networks (SSNs) for second-level sequence grouping into network sequence clusters (NSCs). At 100% sequence similarity in SWARM-SSNs, NSC numbers decreased from 7.9-fold overestimation without abundance filter, to 4.5-fold overestimation when an abundance filter was applied. For the DADA2-SSN approach, NSC numbers decreased from 3.5-fold to 3-fold overestimation. Rand index cluster analyses predicted best binning results between 97% and 94% sequence similarity for both DADA2-SSNs and SWARM-SSNs. Depending on the ecological questions addressed in an environmental sequencing study with protists we recommend ASVs as replacement for OTUs, best in combination with SSNs.
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Affiliation(s)
- Dominik Forster
- Department of Ecology, University of Kaiserslautern, Kaiserslautern, Germany
| | - Guillaume Lentendu
- Department of Ecology, University of Kaiserslautern, Kaiserslautern, Germany
| | - Sabine Filker
- Department of Molecular Ecology, University of Kaiserslautern, Kaiserslautern, Germany
| | - Elyssa Dubois
- Department of Ecology, University of Kaiserslautern, Kaiserslautern, Germany
| | - Thomas A Wilding
- Scottish Association for Marine Science, Scottish Marine Institute, Oban, Scotland, UK
| | - Thorsten Stoeck
- Department of Ecology, University of Kaiserslautern, Kaiserslautern, Germany
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37
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Zhang T, Fan X, Gao F, Al-Farraj SA, El-Serehy HA, Song W. Further analyses on the phylogeny of the subclass Scuticociliatia (Protozoa, Ciliophora) based on both nuclear and mitochondrial data. Mol Phylogenet Evol 2019; 139:106565. [PMID: 31326515 DOI: 10.1016/j.ympev.2019.106565] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2019] [Revised: 07/13/2019] [Accepted: 07/17/2019] [Indexed: 11/24/2022]
Abstract
So far, the phylogenetic studies on ciliated protists have mainly based on single locus, the nuclear ribosomal DNA (rDNA). In order to avoid the limitations of single gene/genome trees and to add more data to systematic analyses, information from mitochondrial DNA sequence has been increasingly used in different lineages of ciliates. The systematic relationships in the subclass Scuticociliatia are extremely confused and largely unresolved based on nuclear genes. In the present study, we have characterized 72 new sequences, including 40 mitochondrial cytochrome oxidase c subunit I (COI) sequences, 29 mitochondrial small subunit ribosomal DNA (mtSSU-rDNA) sequences and three nuclear small subunit ribosomal DNA (nSSU-rDNA) sequences from 47 isolates of 44 morphospecies. Phylogenetic analyses based on single gene as well as concatenated data were performed and revealed: (1) compared to mtSSU-rDNA, COI gene reveals more consistent relationships with those of nSSU-rDNA; (2) the secondary structures of mtSSU-rRNA V4 region are predicted and compared in scuticociliates, which can contribute to discrimination of closely related species; (3) neither nuclear nor mitochondrial data support the monophyly of the order Loxocephalida, which may represent some divergent and intermediate lineages between the subclass Scuticociliatia and Hymenostomatia; (4) the assignments of thigmotrichids to the order Pleuronematida and the confused taxon Sulcigera comosa to the genus Histiobalantium are confirmed by mitochondrial genes; (5) both nuclear and mitochondrial data reveal that the species in the family Peniculistomatidae always group in the genus Pleuronema, suggesting that peniculistomatids are more likely evolved from Pleuronema-like ancestors; (6) mitochondrial genes support the monophyly of the order Philasterida, but the relationships among families of the order Philasterida remain controversial due to the discrepancies between their morphological and molecular data.
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Affiliation(s)
- Tengteng Zhang
- Institute of Evolution & Marine Biodiversity, Ocean University of China, Qingdao 266003, China; Key Laboratory of Mariculture (Ocean University of China), Ministry of Education, Qingdao 266003, China
| | - Xinpeng Fan
- School of Life Sciences, East China Normal University, Shanghai 200241 China
| | - Feng Gao
- Institute of Evolution & Marine Biodiversity, Ocean University of China, Qingdao 266003, China; Key Laboratory of Mariculture (Ocean University of China), Ministry of Education, Qingdao 266003, China.
| | - Saleh A Al-Farraj
- Zoology Department, College of Science, King Saud University, Riyadh 11451, Saudi Arabia
| | - Hamed A El-Serehy
- Zoology Department, College of Science, King Saud University, Riyadh 11451, Saudi Arabia
| | - Weibo Song
- Institute of Evolution & Marine Biodiversity, Ocean University of China, Qingdao 266003, China; Key Laboratory of Mariculture (Ocean University of China), Ministry of Education, Qingdao 266003, China; Laboratory for Marine Biology and Biotechnology, Qingdao National Laboratory for Marine Science and Technology, Qingdao 266003, China.
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38
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Ning Y, Chen L, Sheng Y, Zhang H, Al-Farraj SA, Huang J. Morphology, morphogenesis, and molecular phylogeny of a soil ciliate, Gonostomum kuehnelti Foissner, 1987 (Ciliophora, Hypotrichia), from northwestern China. J NAT HIST 2019. [DOI: 10.1080/00222933.2019.1634771] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Affiliation(s)
- Yingzhi Ning
- Laboratory of Microbiota, College of Life Science, Northwest Normal University, Lanzhou, China
| | - Lingyun Chen
- Laboratory of Microbiota, College of Life Science, Northwest Normal University, Lanzhou, China
| | - Yalan Sheng
- Institute of Evolution and Marine Biodiversity, Ocean University of China, Qingdao, China
| | - Huiru Zhang
- Laboratory of Microbiota, College of Life Science, Northwest Normal University, Lanzhou, China
| | | | - Jie Huang
- Key Laboratory of Aquatic Biodiversity and Conservation of Chinese Academy of Sciences, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, China
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39
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Chen X, Jiang Y, Gao F, Zheng W, Krock TJ, Stover NA, Lu C, Katz LA, Song W. Genome analyses of the new model protist Euplotes vannus focusing on genome rearrangement and resistance to environmental stressors. Mol Ecol Resour 2019; 19:1292-1308. [PMID: 30985983 DOI: 10.1111/1755-0998.13023] [Citation(s) in RCA: 46] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2019] [Revised: 04/05/2019] [Accepted: 04/08/2019] [Indexed: 12/11/2022]
Abstract
As a model organism for studies of cell and environmental biology, the free-living and cosmopolitan ciliate Euplotes vannus shows intriguing features like dual genome architecture (i.e., separate germline and somatic nuclei in each cell/organism), "gene-sized" chromosomes, stop codon reassignment, programmed ribosomal frameshifting (PRF) and strong resistance to environmental stressors. However, the molecular mechanisms that account for these remarkable traits remain largely unknown. Here we report a combined analysis of de novo assembled high-quality macronuclear (MAC; i.e., somatic) and partial micronuclear (MIC; i.e., germline) genome sequences for E. vannus, and transcriptome profiling data under varying conditions. The results demonstrate that: (a) the MAC genome contains more than 25,000 complete "gene-sized" nanochromosomes (~85 Mb haploid genome size) with the N50 ~2.7 kb; (b) although there is a high frequency of frameshifting at stop codons UAA and UAG, we did not observe impaired transcript abundance as a result of PRF in this species as has been reported for other euplotids; (c) the sequence motif 5'-TA-3' is conserved at nearly all internally-eliminated sequence (IES) boundaries in the MIC genome, and chromosome breakage sites (CBSs) are duplicated and retained in the MAC genome; (d) by profiling the weighted correlation network of genes in the MAC under different environmental stressors, including nutrient scarcity, extreme temperature, salinity and the presence of ammonia, we identified gene clusters that respond to these external physical or chemical stimulations, and (e) we observed a dramatic increase in HSP70 gene transcription under salinity and chemical stresses but surprisingly, not under temperature changes; we link this temperature-resistance to the evolved loss of temperature stress-sensitive elements in regulatory regions. Together with the genome resources generated in this study, which are available online at Euplotes vannus Genome Database (http://evan.ciliate.org), these data provide molecular evidence for understanding the unique biology of highly adaptable microorganisms.
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Affiliation(s)
- Xiao Chen
- Institute of Evolution & Marine Biodiversity, Ocean University of China, Qingdao, China.,Department of Genetics and Development, Columbia University Medical Center, New York, New York
| | - Yaohan Jiang
- Institute of Evolution & Marine Biodiversity, Ocean University of China, Qingdao, China
| | - Feng Gao
- Institute of Evolution & Marine Biodiversity, Ocean University of China, Qingdao, China.,Key Laboratory of Mariculture (Ministry of Education), Ocean University of China, Qingdao, China
| | - Weibo Zheng
- Institute of Evolution & Marine Biodiversity, Ocean University of China, Qingdao, China
| | - Timothy J Krock
- Department of Computer Science and Information Systems, Bradley University, Peoria, Illinois
| | - Naomi A Stover
- Department of Biology, Bradley University, Peoria, Illinois
| | - Chao Lu
- Department of Genetics and Development, Columbia University Medical Center, New York, New York
| | - Laura A Katz
- Department of Biological Sciences, Smith College, Northampton, Massachusetts
| | - Weibo Song
- Institute of Evolution & Marine Biodiversity, Ocean University of China, Qingdao, China.,Laboratory for Marine Biology and Biotechnology, Qingdao National Laboratory for Marine Science and Technology, Qingdao, China
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40
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Song W, Xu D, Zhang Q, Liu W, Warren A, Song W. Taxonomy and phylogeny of two poorly studied genera of marine oligotrich ciliates including descriptions of two new species: Cyrtostrombidium paraboreale sp. n. and Apostrombidium orientale sp. n. (Ciliophora: Spirotrichea). Eur J Protistol 2019; 70:1-16. [PMID: 31176174 DOI: 10.1016/j.ejop.2019.05.001] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2018] [Revised: 05/09/2019] [Accepted: 05/09/2019] [Indexed: 11/19/2022]
Abstract
Although it is widely recognized that oligotrich ciliates are the dominant constituent of microzooplankton communities and perform key functions in energy flow and material cycling in marine microbial food webs, knowledge of their diversity is scant. In the present study, we investigate the oligotrich genera, Cyrtostrombidium and Apostrombidium, with emphasis on their morphology and evolutionary relationships. Three isolates were collected from coastal waters of northern and southern China including two new species, viz., Cyrtostrombidium paraboreale sp. n., Apostrombidium orientale sp. n., and Apostrombidium pseudokielum Xu et al., 2009. Cyrtostrombidium paraboreale sp. n. is characterized by possessing 64-98 cytopharyngeal rods and two macronuclear nodules. Apostrombidium orientale sp. n. is characterized by its somatic kinety consisting of five fragments including a horizontally orientated subterminal fragment and possessing conspicuously long dorsal cilia. Apostrombidium pseudokielum is redescribed based on the new population and a re-examination of the type material. Phylogenetic analyses were performed for the subclass Oligotrichia, incorporating SSU rRNA gene sequences of the three species investigated here. The results indicate that the genus Cyrtostrombidium is monophyletic with C. paraboreale sp. n. occupying the basal position. The genus Apostrombidium is not monophyletic as Varistrombidium kielum is nested within it.
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Affiliation(s)
- Wen Song
- Institute of Evolution and Marine Biodiversity, Ocean University of China, Qingdao 266003, China
| | - Dapeng Xu
- State Key Laboratory of Marine Environmental Science, Institute of Marine Microbes and Ecospheres, College of Ocean and Earth Sciences, Xiamen University, Xiamen 361102, China
| | - Qianqian Zhang
- Yantai Institute of Coastal Zone Research, Chinese Academy of Sciences, Yantai 264003, China
| | - Weiwei Liu
- Key Laboratory of Tropical Marine Bio-resources and Ecology, South China Sea Institute of Oceanology, Chinese Academy of Science, Guangzhou 510301, China
| | - Alan Warren
- Department of Life Sciences, Natural History Museum, Cromwell Road, London SW7 5BD, UK
| | - Weibo Song
- Institute of Evolution and Marine Biodiversity, Ocean University of China, Qingdao 266003, China; Laboratory for Marine Biology and Biotechnology, Qingdao National Laboratory for Marine Science and Technology, Qingdao 266003, China.
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41
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Liu Y, Nan B, Duan L, Cheng T, Bourland WA, Liu M, Zhao Y. A Simple and Rapid Cryopreservation Technique for Ciliates: A Long‐Term Storage Procedure Used for Marine Scuticociliates. J Eukaryot Microbiol 2019; 66:836-848. [DOI: 10.1111/jeu.12730] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2019] [Revised: 02/22/2019] [Accepted: 03/15/2019] [Indexed: 12/25/2022]
Affiliation(s)
- Yongqiang Liu
- Institute of Evolution & Marine Biodiversity Ocean University of China Qingdao 266003 China
- Laboratory for Marine Biology and Biotechnology Qingdao National Laboratory for Marine Science and Technology Qingdao 266003 China
| | - Bei Nan
- Institute of Evolution & Marine Biodiversity Ocean University of China Qingdao 266003 China
- Laboratory for Marine Biology and Biotechnology Qingdao National Laboratory for Marine Science and Technology Qingdao 266003 China
| | - Lili Duan
- Institute of Evolution & Marine Biodiversity Ocean University of China Qingdao 266003 China
- Laboratory for Marine Biology and Biotechnology Qingdao National Laboratory for Marine Science and Technology Qingdao 266003 China
| | - Ting Cheng
- Institute of Evolution & Marine Biodiversity Ocean University of China Qingdao 266003 China
- Laboratory for Marine Biology and Biotechnology Qingdao National Laboratory for Marine Science and Technology Qingdao 266003 China
| | - William A. Bourland
- Department of Biological Sciences Boise State University Boise Idaho 83725‐1515 USA
| | - Mingjian Liu
- Institute of Evolution & Marine Biodiversity Ocean University of China Qingdao 266003 China
| | - Yan Zhao
- Research Centre for Eco‐Environmental Sciences Chinese Academy of Sciences Beijing 100085 China
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42
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Wang Y, Wang C, Jiang Y, Katz LA, Gao F, Yan Y. Further analyses of variation of ribosome DNA copy number and polymorphism in ciliates provide insights relevant to studies of both molecular ecology and phylogeny. SCIENCE CHINA-LIFE SCIENCES 2019; 62:203-214. [PMID: 30671886 DOI: 10.1007/s11427-018-9422-5] [Citation(s) in RCA: 64] [Impact Index Per Article: 12.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Subscribe] [Scholar Register] [Received: 09/08/2018] [Accepted: 11/06/2018] [Indexed: 11/26/2022]
Abstract
Sequence-based approaches, such as analyses of ribosome DNA (rDNA) clone libraries and high-throughput amplicon sequencing, have been used extensively to infer evolutionary relationships and elucidate the biodiversity in microbial communities. However, recent studies demonstrate both rDNA copy number variation and intra-individual (intra-genomic) sequence variation in many organisms, which challenges the application of the rDNA-based surveys. In ciliates, an ecologically important clade of microbial eukaryotes, rDNA copy number and sequence variation are rarely studied. In the present study, we estimate the intraindividual small subunit rDNA (SSU rDNA) copy number and sequence variation in a wide range of taxa covering nine classes and 18 orders of the phylum Ciliophora. Our studies reveal that: (i) intra-individual sequence variation of SSU rDNA is ubiquitous in all groups of ciliates detected and the polymorphic level varies among taxa; (ii) there is a most common version of SSU rDNA sequence in each cell that is highly predominant and may represent the germline micronuclear template; (iii) compared with the most common version, other variant sequences differ in only 1-3 nucleotides, likely generated during macronuclear (somatic) amplification; (iv) the intra-cell sequence variation is unlikely to impact phylogenetic analyses; (v) the rDNA copy number in ciliates is highly variable, ranging from 103 to 106, with the highest record in Stentor roeselii. Overall, these analyses indicate the need for careful consideration of SSU rDNA variation in analyses of the role of ciliates in ecosystems.
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Affiliation(s)
- Yurui Wang
- Institute of Evolution & Marine Biodiversity, Ocean University of China, Qingdao, 266003, China
- Key Laboratory of Mariculture, Ocean University of China, Ministry of Education, Qingdao, 266003, China
| | - Chundi Wang
- Institute of Evolution & Marine Biodiversity, Ocean University of China, Qingdao, 266003, China
- Key Laboratory of Mariculture, Ocean University of China, Ministry of Education, Qingdao, 266003, China
| | - Yaohan Jiang
- Institute of Evolution & Marine Biodiversity, Ocean University of China, Qingdao, 266003, China
- Key Laboratory of Mariculture, Ocean University of China, Ministry of Education, Qingdao, 266003, China
| | - Laura A Katz
- Department of Biological Sciences, Smith College, Northampton, MA, 01063, USA
| | - Feng Gao
- Institute of Evolution & Marine Biodiversity, Ocean University of China, Qingdao, 266003, China.
- Key Laboratory of Mariculture, Ocean University of China, Ministry of Education, Qingdao, 266003, China.
| | - Ying Yan
- Institute of Evolution & Marine Biodiversity, Ocean University of China, Qingdao, 266003, China.
- Key Laboratory of Mariculture, Ocean University of China, Ministry of Education, Qingdao, 266003, China.
- Department of Biological Sciences, Smith College, Northampton, MA, 01063, USA.
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43
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Jiang Y, Zhang T, Vallesi A, Yang X, Gao F. Time-course analysis of nuclear events during conjugation in the marine ciliate Euplotes vannus and comparison with other ciliates (Protozoa, Ciliophora). Cell Cycle 2019; 18:288-298. [PMID: 30563432 DOI: 10.1080/15384101.2018.1558871] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
Ciliates represent a morphologically and genetically distinct group of single-celled eukaryotes that segregate germline and somatic functions into two types of nuclei and exhibit complex cytogenetic events during the sexual process of conjugation, which is under the control of the so-called "mating type systems". Studying conjugation in ciliates may provide insight into our understanding of the origins and evolution of sex and fertilization. In the present work, we studied in detail the sexual process of conjugation using the model species Euplotes vannus, and compared these nuclear events with those occurring in other ciliates. Our results indicate that in E. vannus: 1) conjugation requires about 75 hours to complete: the longest step is the development of the new macronucleus (ca. 64h), followed by the nuclear division of meiosis I (5h); the mitotic divisions usually take only 2h; 2) there are three prezygotic divisions (mitosis and meiosis I and II), and two of the eight resulting nuclei become pronuclei; 3) after the exchange and fusion of the pronuclei, two postzygotic divisions occur; two of the four products differentiate into the new micronucleus and macronucleus, respectively, and the parental macronucleus degenerates completely; 4) comparison of the nuclear events during conjugation in different ciliates reveals that there are generally three prezygotic divisions while the number of postzygotic divisions is highly variable. These results can serve as reference to investigate the mating type system operating in this species and to analyze genes involved in the different steps of the sexual process.
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Affiliation(s)
- Yaohan Jiang
- a Institute of Evolution and Marine Biodiversity , Ocean University of China , Qingdao , China.,b Ministry of Education , Key Laboratory of Mariculture (Ocean University of China) , Qingdao , China
| | - Tengteng Zhang
- a Institute of Evolution and Marine Biodiversity , Ocean University of China , Qingdao , China.,b Ministry of Education , Key Laboratory of Mariculture (Ocean University of China) , Qingdao , China
| | - Adriana Vallesi
- c Laboratory of Eukaryotic Microbiology and Animal Biology , University of Camerino , Camerino , Italy
| | - Xianyu Yang
- d College of Animal Science and Technology , Zhejiang A&F University , Hangzhou , China
| | - Feng Gao
- a Institute of Evolution and Marine Biodiversity , Ocean University of China , Qingdao , China.,b Ministry of Education , Key Laboratory of Mariculture (Ocean University of China) , Qingdao , China
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Zhao Y, Yi Z, Warren A, Song W. Species delimitation for the molecular taxonomy and ecology of the widely distributed microbial eukaryote genus Euplotes (Alveolata, Ciliophora). Proc Biol Sci 2019; 285:rspb.2017.2159. [PMID: 29367393 DOI: 10.1098/rspb.2017.2159] [Citation(s) in RCA: 40] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2017] [Accepted: 01/03/2018] [Indexed: 11/12/2022] Open
Abstract
Recent advances in high-throughput sequencing and metabarcoding technologies are revolutionizing our understanding of the diversity and ecology of microbial eukaryotes (protists). The interpretation of protist diversity and the elucidation of their ecosystem function are, however, impeded by problems with species delimitation, especially as it applies to molecular taxonomy. Here, using the ciliate Euplotes as an example, we describe approaches for species delimitation based on integrative taxonomy by using evolutionary and ecological perspectives and selecting the most appropriate metabarcoding gene markers as proxies for species units. Our analyses show that: Euplotes (sensu lato) comprises six distinct clades, mainly as result of ecological speciation; the validity of the genera Euplotes (sensu stricto), Euplotoides, Euplotopsis and Moneuplotes are not supported; the vannus-type group, which includes species without distinct morphological differences, seems to be undergoing incipient speciation and contains cryptic species; the hypervariable V4 region of the small subunit rDNA and D1-D2 region of the large subunit rDNA are the promising candidates for general species delimitation in Euplotes.
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Affiliation(s)
- Yan Zhao
- Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, People's Republic of China .,Laboratory of Protozoology, Institute of Evolution and Marine Biodiversity, Ocean University of China, Qingdao 266003, People's Republic of China
| | - Zhenzhen Yi
- Guangzhou Key Laboratory of Subtropical Biodiversity and Biomonitoring, School of Life Science, South China Normal University, Guangzhou 510631, People's Republic of China
| | - Alan Warren
- Department of Life Sciences, Natural History Museum, London SW7 5BD, UK
| | - Weibo Song
- Laboratory of Protozoology, Institute of Evolution and Marine Biodiversity, Ocean University of China, Qingdao 266003, People's Republic of China.,Laboratory for Marine Biology and Biotechnology, Qingdao National Laboratory for Marine Science and Technology, Qingdao 266003, People's Republic of China
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Lu X, Gentekaki E, Xu Y, Huang L, Li Y, Lu X, Zhao Y, Lin X, Yi Z. Intra-population genetic diversity and its effects on outlining genetic diversity of ciliate populations: Using Paramecium multimicronucleatum as an example. Eur J Protistol 2018; 67:142-150. [PMID: 30616107 DOI: 10.1016/j.ejop.2018.12.005] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2018] [Revised: 12/16/2018] [Accepted: 12/21/2018] [Indexed: 01/06/2023]
Abstract
Questions regarding ciliate distribution (endemism vs. cosmopolitanism) and degree of genetic diversity (high vs. low) remain unsettled, even when the same organism is under investigation. Presence of genes with high copy number and amplification of non-dominant haplotypes might account for the observed discordance in these studies. Herein, we used direct PCR and cloning sequencing to examine intra-population sequence diversity and its effect on assessments of phylogeography of Paramecium multimicronucleatum. Totally, 381 ITS1-5.8S rDNA-ITS2-28S rDNA and 304 mitochondrial cytochrome oxidase subunit I (COI) gene sequences were generated for 18 populations of P. multimicronucleatum. The following results were obtained: (1) Direct sequencing of PCR products captured the dominant ITS and LSU haplotypes, indicating that it is an appropriate strategy for constructing phylogeography of large-scale spatial populations. (2) Deep cloning was deemed more appropriate for the COI gene for population level studies, as direct sequencing could not easily capture the dominant haplotypes. (3) No endemic populations of P. multinucleatum were noted, indicating origin from a single founder population. (4) Nuclear genetic diversity within temporal populations was high, but only the dominant haplotypes seemed to be passed on to subsequent generations.
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Affiliation(s)
- Xuefen Lu
- Laboratory of Protozoology, Guangzhou Key Laboratory of Subtropical Biodiversity and Biomonitoring, School of Life Science, South China Normal University, Guangzhou 510631, China
| | - Eleni Gentekaki
- School of Science, Mae Fah Luang University, Chiang Rai 57100, Thailand
| | - Yiwei Xu
- Laboratory of Protozoology, Guangzhou Key Laboratory of Subtropical Biodiversity and Biomonitoring, School of Life Science, South China Normal University, Guangzhou 510631, China
| | - Lijuan Huang
- Laboratory of Protozoology, Guangzhou Key Laboratory of Subtropical Biodiversity and Biomonitoring, School of Life Science, South China Normal University, Guangzhou 510631, China
| | - Yunyi Li
- Laboratory of Protozoology, Guangzhou Key Laboratory of Subtropical Biodiversity and Biomonitoring, School of Life Science, South China Normal University, Guangzhou 510631, China
| | - Xiaotong Lu
- Laboratory of Protozoology, Guangzhou Key Laboratory of Subtropical Biodiversity and Biomonitoring, School of Life Science, South China Normal University, Guangzhou 510631, China
| | - Yan Zhao
- Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China
| | - Xiaofeng Lin
- Laboratory of Protozoology, Guangzhou Key Laboratory of Subtropical Biodiversity and Biomonitoring, School of Life Science, South China Normal University, Guangzhou 510631, China
| | - Zhenzhen Yi
- Laboratory of Protozoology, Guangzhou Key Laboratory of Subtropical Biodiversity and Biomonitoring, School of Life Science, South China Normal University, Guangzhou 510631, China.
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Sheng Y, He M, Zhao F, Shao C, Miao M. Phylogenetic relationship analyses of complicated class Spirotrichea based on transcriptomes from three diverse microbial eukaryotes: Uroleptopsis citrina, Euplotes vannus and Protocruzia tuzeti. Mol Phylogenet Evol 2018; 129:338-345. [DOI: 10.1016/j.ympev.2018.06.025] [Citation(s) in RCA: 33] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2018] [Accepted: 06/13/2018] [Indexed: 11/25/2022]
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47
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Zheng W, Wang C, Yan Y, Gao F, Doak TG, Song W. Insights into an Extensively Fragmented Eukaryotic Genome: De Novo Genome Sequencing of the Multinuclear Ciliate Uroleptopsis citrina. Genome Biol Evol 2018; 10:883-894. [PMID: 29608728 PMCID: PMC5863220 DOI: 10.1093/gbe/evy055] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/01/2018] [Indexed: 02/04/2023] Open
Abstract
Ciliated protists are a large group of single-celled eukaryotes with separate germline and somatic nuclei in each cell. The somatic genome is developed from the zygotic nucleus through a series of chromosomal rearrangements, including fragmentation, DNA elimination, de novo telomere addition, and DNA amplification. This unique feature makes them perfect models for research in genome biology and evolution. However, genomic research of ciliates has been limited to a few species, owing to problems with DNA contamination and obstacles in cultivation. Here, we introduce a method combining telomere-primer PCR amplification and high-throughput sequencing, which can reduce DNA contamination and obtain genomic data efficiently. Based on this method, we report a draft somatic genome of a multimacronuclear ciliate, Uroleptopsis citrina. 1) The telomeric sequence in U. citrina is confirmed to be C4A4C4A4C4 by directly blunt-end cloning. 2) Genomic analysis of the resulting chromosomes shows a "one-gene one-chromosome" pattern, with a small number of multiple-gene chromosomes. 3) Amino acid usage is analyzed, and reassignment of stop codons is confirmed. 4) Chromosomal analysis shows an obvious asymmetrical GC skew and high bias between A and T in the subtelomeric regions of the sense-strand, with the detection of an 11-bp high AT motif region in the 3' subtelomeric region. 5) The subtelomeric sequence also has an obvious 40 nt strand oscillation of nucleotide ratio. 6) In the 5' subtelomeric region of the coding strand, the distribution of potential TATA-box regions is illustrated, which accumulate between 30 and 50 nt. This work provides a valuable reference for genomic research and furthers our understanding of the dynamic nature of unicellular eukaryotic genomes.
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Affiliation(s)
- Weibo Zheng
- Laboratory of Protozoology, Institute of Evolution & Marine Biodiversity, Ocean University of China, Qingdao, China.,Center for Mechanisms of Evolution, Arizona State University, Tempe, USA
| | - Chundi Wang
- Laboratory of Protozoology, Institute of Evolution & Marine Biodiversity, Ocean University of China, Qingdao, China
| | - Ying Yan
- Laboratory of Protozoology, Institute of Evolution & Marine Biodiversity, Ocean University of China, Qingdao, China
| | - Feng Gao
- Laboratory of Protozoology, Institute of Evolution & Marine Biodiversity, Ocean University of China, Qingdao, China.,Key Laboratory of Mariculture, Ocean University of China, Ministry of Education, Qingdao, China
| | - Thomas G Doak
- Department of Biology, Indiana University, Bloomington.,National Center for Genome Analysis Support, Indiana University, Bloomington
| | - Weibo Song
- Laboratory of Protozoology, Institute of Evolution & Marine Biodiversity, Ocean University of China, Qingdao, China.,Laboratory for Marine Biology and Biotechnology, Qingdao National Laboratory for Marine Science and Technology, Qingdao, China
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48
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Zhang T, Wang C, Katz LA, Gao F. A paradox: rapid evolution rates of germline-limited sequences are associated with conserved patterns of rearrangements in cryptic species of Chilodonella uncinata (Protista, Ciliophora). SCIENCE CHINA-LIFE SCIENCES 2018; 61:1071-1078. [DOI: 10.1007/s11427-018-9333-1] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/28/2018] [Accepted: 06/06/2018] [Indexed: 10/28/2022]
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49
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Morphology and systematics of two freshwater Frontonia species (Ciliophora, Peniculida) from northeastern China, with comparisons among the freshwater Frontonia spp. Eur J Protistol 2018; 63:105-116. [DOI: 10.1016/j.ejop.2018.01.002] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2017] [Revised: 01/06/2018] [Accepted: 01/08/2018] [Indexed: 11/24/2022]
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50
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Chen X, Wang Y, Sheng Y, Warren A, Gao S. GPSit: An automated method for evolutionary analysis of nonculturable ciliated microeukaryotes. Mol Ecol Resour 2018; 18:700-713. [DOI: 10.1111/1755-0998.12750] [Citation(s) in RCA: 27] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2017] [Revised: 12/25/2017] [Accepted: 12/26/2017] [Indexed: 12/20/2022]
Affiliation(s)
- Xiao Chen
- Institute of Evolution & Marine Biodiversity; Ocean University of China; Qingdao China
- Laboratory for Marine Biology and Biotechnology; Qingdao National Laboratory for Marine Science and Technology; Qingdao China
| | - Yurui Wang
- Institute of Evolution & Marine Biodiversity; Ocean University of China; Qingdao China
- Laboratory for Marine Biology and Biotechnology; Qingdao National Laboratory for Marine Science and Technology; Qingdao China
| | - Yalan Sheng
- Institute of Evolution & Marine Biodiversity; Ocean University of China; Qingdao China
- Laboratory for Marine Biology and Biotechnology; Qingdao National Laboratory for Marine Science and Technology; Qingdao China
| | - Alan Warren
- Department of Life Sciences; Natural History Museum; London UK
| | - Shan Gao
- Institute of Evolution & Marine Biodiversity; Ocean University of China; Qingdao China
- Laboratory for Marine Biology and Biotechnology; Qingdao National Laboratory for Marine Science and Technology; Qingdao China
- College of Marine Life Sciences; Ocean University of China; Qingdao China
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