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Queiroz VF, Tatara JM, Botelho BB, Rodrigues RAL, Almeida GMDF, Abrahao JS. The consequences of viral infection on protists. Commun Biol 2024; 7:306. [PMID: 38462656 PMCID: PMC10925606 DOI: 10.1038/s42003-024-06001-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2023] [Accepted: 02/29/2024] [Indexed: 03/12/2024] Open
Abstract
Protists encompass a vast widely distributed group of organisms, surpassing the diversity observed in metazoans. Their diverse ecological niches and life forms are intriguing characteristics that render them valuable subjects for in-depth cell biology studies. Throughout history, viruses have played a pivotal role in elucidating complex cellular processes, particularly in the context of cellular responses to viral infections. In this comprehensive review, we provide an overview of the cellular alterations that are triggered in specific hosts following different viral infections and explore intricate biological interactions observed in experimental conditions using different host-pathogen groups.
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Affiliation(s)
- Victoria Fulgencio Queiroz
- Federal University of Minas Gerais, Institute of Biological Sciences, Department of Microbiology, Belo Horizonte, Minas Gerais, Brazil
| | - Juliana Miranda Tatara
- The Norwegian College of Fishery Science, Faculty of Biosciences, Fisheries and Economics, UiT - The Arctic University of Norway, Tromsø, Norway
| | - Bruna Barbosa Botelho
- Federal University of Minas Gerais, Institute of Biological Sciences, Department of Microbiology, Belo Horizonte, Minas Gerais, Brazil
| | - Rodrigo Araújo Lima Rodrigues
- Federal University of Minas Gerais, Institute of Biological Sciences, Department of Microbiology, Belo Horizonte, Minas Gerais, Brazil
| | - Gabriel Magno de Freitas Almeida
- The Norwegian College of Fishery Science, Faculty of Biosciences, Fisheries and Economics, UiT - The Arctic University of Norway, Tromsø, Norway.
| | - Jonatas Santos Abrahao
- Federal University of Minas Gerais, Institute of Biological Sciences, Department of Microbiology, Belo Horizonte, Minas Gerais, Brazil
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2
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Coy SR, Utama B, Spurlin JW, Kim JG, Deshmukh H, Lwigale P, Nagasaki K, Correa AMS. Visualization of RNA virus infection in a marine protist with a universal biomarker. Sci Rep 2023; 13:5813. [PMID: 37037845 PMCID: PMC10086069 DOI: 10.1038/s41598-023-31507-w] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2022] [Accepted: 03/13/2023] [Indexed: 04/12/2023] Open
Abstract
Half of the marine virosphere is hypothesized to be RNA viruses (kingdom Orthornavirae) that infect abundant micro-eukaryotic hosts (e.g. protists). To test this, quantitative approaches that broadly track infections in situ are needed. Here, we describe a technique-dsRNA-Immunofluorescence (dsRIF)-that uses a double-stranded RNA (dsRNA) targeting monoclonal antibody to assess host infection status based on the presence of dsRNA, a replicative intermediate of all Orthornavirae infections. We show that the dinoflagellate Heterocapsa circularisquama produces dsRIF signal ~ 1000 times above background autofluorescence when infected by the + ssRNA virus HcRNAV. dsRNA-positive virocells were detected across > 50% of the 48-h infection cycle and accumulated to represent at least 63% of the population. Photosynthetic and chromosomal integrity remained intact during peak replication, indicating HcRNAV infection does not interrupt these processes. This work validates the use of dsRIF on marine RNA viruses and their hosts, setting the stage for quantitative environmental applications that will accelerate understanding of virus-driven ecosystem impacts.
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Affiliation(s)
- Samantha R Coy
- Department of Biosciences, Rice University, Houston, TX, USA.
- Department of Oceanography, Texas A&M University, College Station, TX, USA.
| | - Budi Utama
- Shared Equipment Authority, Rice University, Houston, TX, USA
| | - James W Spurlin
- Department of Biosciences, Rice University, Houston, TX, USA
| | - Julia G Kim
- Department of Biosciences, Rice University, Houston, TX, USA
| | | | - Peter Lwigale
- Department of Biosciences, Rice University, Houston, TX, USA
| | - Keizo Nagasaki
- Faculty of Science and Technology, Kochi University, Nankoku, Kochi, 783-8502, Japan
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3
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Sadeghi M, Tomaru Y, Ahola T. RNA Viruses in Aquatic Unicellular Eukaryotes. Viruses 2021; 13:v13030362. [PMID: 33668994 PMCID: PMC7996518 DOI: 10.3390/v13030362] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2020] [Revised: 02/05/2021] [Accepted: 02/22/2021] [Indexed: 12/24/2022] Open
Abstract
Increasing sequence information indicates that RNA viruses constitute a major fraction of marine virus assemblages. However, only 12 RNA virus species have been described, infecting known host species of marine single-celled eukaryotes. Eight of these use diatoms as hosts, while four are resident in dinoflagellate, raphidophyte, thraustochytrid, or prasinophyte species. Most of these belong to the order Picornavirales, while two are divergent and fall into the families Alvernaviridae and Reoviridae. However, a very recent study has suggested that there is extraordinary diversity in aquatic RNA viromes, describing thousands of viruses, many of which likely use protist hosts. Thus, RNA viruses are expected to play a major ecological role for marine unicellular eukaryotic hosts. In this review, we describe in detail what has to date been discovered concerning viruses with RNA genomes that infect aquatic unicellular eukaryotes.
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Affiliation(s)
- Mohammadreza Sadeghi
- Department of Microbiology, Faculty of Agriculture and Forestry, University of Helsinki, 00014 Helsinki, Finland
- Correspondence: (M.S.); (T.A.)
| | - Yuji Tomaru
- Environment and Fisheries Applied Techniques Research Department, Fisheries Technology Institute, Fisheries Research and Education Agency, Hatsukaichi, Hiroshima 739-0452, Japan;
| | - Tero Ahola
- Department of Microbiology, Faculty of Agriculture and Forestry, University of Helsinki, 00014 Helsinki, Finland
- Correspondence: (M.S.); (T.A.)
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4
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Horas EL, Theodosiou L, Becks L. Why Are Algal Viruses Not Always Successful? Viruses 2018; 10:v10090474. [PMID: 30189587 PMCID: PMC6165140 DOI: 10.3390/v10090474] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2018] [Revised: 08/31/2018] [Accepted: 09/02/2018] [Indexed: 12/14/2022] Open
Abstract
Algal viruses are considered to be key players in structuring microbial communities and biogeochemical cycles due to their abundance and diversity within aquatic systems. Their high reproduction rates and short generation times make them extremely successful, often with immediate and strong effects for their hosts and thus in biological and abiotic environments. There are, however, conditions that decrease their reproduction rates and make them unsuccessful with no or little immediate effects. Here, we review the factors that lower viral success and divide them into intrinsic—when they are related to the life cycle traits of the virus—and extrinsic factors—when they are external to the virus and related to their environment. Identifying whether and how algal viruses adapt to disadvantageous conditions will allow us to better understand their role in aquatic systems. We propose important research directions such as experimental evolution or the resurrection of extinct viruses to disentangle the conditions that make them unsuccessful and the effects these have on their surroundings.
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Affiliation(s)
- Elena L Horas
- Community Dynamics Group, Max-Planck for Evolutionary Biology, 24306 Plön, Germany.
- Limnology-Aquatic Ecology and Evolution, Limnological Institute, University of Konstanz, 78464 Konstanz, Germany.
| | - Loukas Theodosiou
- Community Dynamics Group, Max-Planck for Evolutionary Biology, 24306 Plön, Germany.
- Department of Microbial Population Biology, Max-Planck for Evolutionary Biology, 24306 Plön, Germany.
| | - Lutz Becks
- Community Dynamics Group, Max-Planck for Evolutionary Biology, 24306 Plön, Germany.
- Limnology-Aquatic Ecology and Evolution, Limnological Institute, University of Konstanz, 78464 Konstanz, Germany.
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5
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Zhou J, Richlen ML, Sehein TR, Kulis DM, Anderson DM, Cai Z. Microbial Community Structure and Associations During a Marine Dinoflagellate Bloom. Front Microbiol 2018; 9:1201. [PMID: 29928265 PMCID: PMC5998739 DOI: 10.3389/fmicb.2018.01201] [Citation(s) in RCA: 68] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2017] [Accepted: 05/16/2018] [Indexed: 11/13/2022] Open
Abstract
Interactions between microorganisms and algae during bloom events significantly impacts their physiology, alters ambient chemistry, and shapes ecosystem diversity. The potential role these interactions have in bloom development and decline are also of particular interest given the ecosystem impacts of algal blooms. We hypothesized that microbial community structure and succession is linked to specific bloom stages, and reflects complex interactions among taxa comprising the phycosphere environment. This investigation used pyrosequencing and correlation approaches to assess patterns and associations among bacteria, archaea, and microeukaryotes during a spring bloom of the dinoflagellate Alexandrium catenella. Within the bacterial community, Gammaproteobacteria and Bacteroidetes were predominant during the initial bloom stage, while Alphaproteobacteria, Cyanobacteria, and Actinobacteria were the most abundant taxa present during bloom onset and termination. In the archaea biosphere, methanogenic members were present during the early bloom period while the majority of species identified in the late bloom stage were ammonia-oxidizing archaea and Halobacteriales. Dinoflagellates were the major eukaryotic group present during most stages of the bloom, whereas a mixed assemblage comprising diatoms, green-algae, rotifera, and other microzooplankton were present during bloom termination. Temperature and salinity were key environmental factors associated with changes in bacterial and archaeal community structure, respectively, whereas inorganic nitrogen and inorganic phosphate were associated with eukaryotic variation. The relative contribution of environmental parameters measured during the bloom to variability among samples was 35.3%. Interaction analysis showed that Maxillopoda, Spirotrichea, Dinoflagellata, and Halobacteria were keystone taxa within the positive-correlation network, while Halobacteria, Dictyochophyceae, Mamiellophyceae, and Gammaproteobacteria were the main contributors to the negative-correlation network. The positive and negative relationships were the primary drivers of mutualist and competitive interactions that impacted algal bloom fate, respectively. Functional predictions showed that blooms enhance microbial carbohydrate and energy metabolism, and alter the sulfur cycle. Our results suggest that microbial community structure is strongly linked to bloom progression, although specific drivers of community interactions and responses are not well understood. The importance of considering biotic interactions (e.g., competition, symbiosis, and predation) when investigating the link between microbial ecological behavior and an algal bloom's trajectory is also highlighted.
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Affiliation(s)
- Jin Zhou
- Shenzhen Public Platform for Screening and Application of Marine Microbial Resources, Graduate School at Shenzhen, Tsinghua University, Shenzhen, China
| | - Mindy L. Richlen
- Department of Biology, Woods Hole Oceanographic Institution, Woods Hole, MA, United States
| | - Taylor R. Sehein
- Department of Biology, Woods Hole Oceanographic Institution, Woods Hole, MA, United States
| | - David M. Kulis
- Department of Biology, Woods Hole Oceanographic Institution, Woods Hole, MA, United States
| | - Donald M. Anderson
- Department of Biology, Woods Hole Oceanographic Institution, Woods Hole, MA, United States
| | - Zhonghua Cai
- Shenzhen Public Platform for Screening and Application of Marine Microbial Resources, Graduate School at Shenzhen, Tsinghua University, Shenzhen, China
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Kang BS, Eom CY, Kim W, Kim PI, Ju SY, Ryu J, Han GH, Oh JI, Cho H, Baek SH, Kim G, Kim M, Hyun J, Jin E, Kim SW. Construction of target-specific virus-like particles for the delivery of algicidal compounds to harmful algae. Environ Microbiol 2014; 17:1463-74. [DOI: 10.1111/1462-2920.12650] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2014] [Revised: 09/23/2014] [Accepted: 09/26/2014] [Indexed: 11/27/2022]
Affiliation(s)
- Beom Sik Kang
- School of Life Science and Biotechnology; Kyungpook National University; Daegu 702-701 Korea
| | - Chi-Yong Eom
- NanoBio Convergence Research Team; Western Seoul Center; Korea Basic Science Institute; Seoul 120-750 Korea
| | - Wonduck Kim
- Department of Environmental Engineering and Pioneer Research Center for Controlling of Harmful Algal Bloom; Chosun University; Gwangju 501-759 Korea
| | - Pyoung il Kim
- Department of Environmental Engineering and Pioneer Research Center for Controlling of Harmful Algal Bloom; Chosun University; Gwangju 501-759 Korea
| | - Sun Yi Ju
- Department of Environmental Engineering and Pioneer Research Center for Controlling of Harmful Algal Bloom; Chosun University; Gwangju 501-759 Korea
| | - Jaewon Ryu
- Department of Environmental Engineering and Pioneer Research Center for Controlling of Harmful Algal Bloom; Chosun University; Gwangju 501-759 Korea
| | - Gui Hwan Han
- Department of Environmental Engineering and Pioneer Research Center for Controlling of Harmful Algal Bloom; Chosun University; Gwangju 501-759 Korea
| | - Jeong-Il Oh
- Department of Microbiology; Pusan University; Pusan 609-735 Korea
| | - Hoon Cho
- Department of Polymer Science and Engineering; Chosun University; Gwangju 501-759 Korea
| | - Seung Ho Baek
- South Sea Institute; Korea Ocean Research and Development Institute; Geoje 656-830 Korea
| | - Gueeda Kim
- Department of Life Science and Research Institute for Natural Sciences; Hanyang University; Seoul 133-791 Korea
| | - Minju Kim
- Department of Life Science and Research Institute for Natural Sciences; Hanyang University; Seoul 133-791 Korea
| | - Jaekyung Hyun
- Division of Electron Microscopic Research; Korea Basic Science Institute; Daejeon 305-333 Korea
| | - EonSeon Jin
- Department of Life Science and Research Institute for Natural Sciences; Hanyang University; Seoul 133-791 Korea
| | - Si Wouk Kim
- Department of Environmental Engineering and Pioneer Research Center for Controlling of Harmful Algal Bloom; Chosun University; Gwangju 501-759 Korea
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Nakayama N, Fujimoto A, Kawami H, Tomaru Y, Hata N, Nagasaki K. High interaction variability of the bivalve-killing dinoflagellate Heterocapsa circularisquama strains and their single-stranded RNA virus HcRNAV isolates. Microbes Environ 2012; 28:112-9. [PMID: 23268792 PMCID: PMC4070693 DOI: 10.1264/jsme2.me12106] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
HcRNAV is a single-stranded RNA (ssRNA) virus that specifically infects the bivalve-killing dinoflagellate, Heterocapsa circularisquama. HcRNAV strains are grouped into 2 types (UA and CY), based on intra-species host specificity and the amino acid sequence of the major capsid protein (MCP). In the present study, we report the isolation of novel HcRNAV clones (n=51) lytic to the H. circularisquama strains, HU9433-P, HCLG-1, 05HC05 and 05HC06. HcRNAV34, HcRNAV109, HcRNAV641, and HcRNAV659, which displayed lytic activity against the strains, HU9433-P, HCLG-1, 05HC05, and 05HC06, respectively, were selected as typical virus clones and were intensively examined. The infection intensity of each host-virus combination was analyzed by examining the algicidal activity, detecting the intracellular replication of the viral RNA as well as the appearance of host cells with a morphologically abnormal nucleus post-infection. Interestingly, the strains, 05HC05 and 05HC06, were markedly sensitive to HcRNAV641 and HcRNAV659, respectively. Tertiary structural modeling predicted 4 unique amino acid (aa) substitutions in HcRNAV659-MCP to be exposed to an ambient water environment, which contributed towards determining its infection specificity. Neighbor-joining analysis of MCP aa sequences from HcRNAV clones revealed 3 clades, namely, the CY type and the UA1 and UA2 subtypes. The HcRNAV clones lytic to HCLG-1 (ex. HcRNAV109), HU9433-P and 05HC05 (ex. HcRNAV34), and 05HC06 (ex. HcRNAV659) were categorized into CY type, UA1 and UA2 subtypes, respectively. The present study highlights the complexity of the H. circularisquama-HcRNAV host-virus system, i.e., clonal variation, microbial control, and ecology in a natural algal population.
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Affiliation(s)
- Natsuko Nakayama
- National Research Institute of Fisheries and Environment of Inland Sea, Hiroshima, Japan
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8
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Park SC, Lee JK, Kim SW, Park Y. Selective algicidal action of peptides against harmful algal bloom species. PLoS One 2011; 6:e26733. [PMID: 22046341 PMCID: PMC3202551 DOI: 10.1371/journal.pone.0026733] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2011] [Accepted: 10/03/2011] [Indexed: 11/29/2022] Open
Abstract
Recently, harmful algal bloom (HAB), also termed “red tide”, has been recognized as a serious problem in marine environments according to climate changes worldwide. Many novel materials or methods to prevent HAB have not yet been employed except for clay dispersion, in which can the resulting sedimentation on the seafloor can also cause alteration in marine ecology or secondary environmental pollution. In the current study, we investigated that antimicrobial peptide have a potential in controlling HAB without cytotoxicity to harmless marine organisms. Here, antimicrobial peptides are proposed as new algicidal compounds in combating HAB cells. HPA3 and HPA3NT3 peptides which exert potent antimicrobial activity via pore forming action in plasma membrane showed that HPA3NT3 reduced the motility of algal cells, disrupted their plasma membrane, and induced the efflux of intracellular components. Against raphidoflagellate such as Heterosigma akashiwo, Chattonella sp., and C. marina, it displayed a rapid lysing action in cell membranes at 1∼4 µM within 2 min. Comparatively, its lysing effects occurred at 8 µM within 1 h in dinoflagellate such as Cochlodium polykrikoides, Prorocentrum micans, and P. minimum. Moreover, its lysing action induced the lysis of chloroplasts and loss of chlorophyll a. In the contrary, this peptide was not effective against Skeletonema costatum, harmless algal cell, even at 256 µM, moreover, it killed only H. akashiwo or C. marina in co-cultivation with S. costatum, indicating to its selective algicidal activity between harmful and harmless algal cells. The peptide was non-hemolytic against red blood cells of Sebastes schlegeli, the black rockfish, at 120 µM. HAB cells were quickly and selectively lysed following treatment of antimicrobial peptides without cytotoxicity to harmless marine organisms. Thus, the antibiotic peptides examined in our study appear to have much potential in effectively controlling HAB with minimal impact on marine ecology.
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Affiliation(s)
- Seong-Cheol Park
- Research Center for Proteinaceous Materials (RCPM), Chosun University, Gwangju, Republic of Korea
| | - Jong-Kook Lee
- Research Center for Proteinaceous Materials (RCPM), Chosun University, Gwangju, Republic of Korea
| | - Si Wouk Kim
- Department of Environmental Engineering, Chosun University, Gwangju, Republic of Korea
| | - Yoonkyung Park
- Research Center for Proteinaceous Materials (RCPM), Chosun University, Gwangju, Republic of Korea
- Department of Biotechnology, Chosun University, Gwangju, Republic of Korea
- * E-mail:
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9
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Thomas R, Grimsley N, Escande ML, Subirana L, Derelle E, Moreau H. Acquisition and maintenance of resistance to viruses in eukaryotic phytoplankton populations. Environ Microbiol 2011; 13:1412-20. [PMID: 21392198 DOI: 10.1111/j.1462-2920.2011.02441.x] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Viruses are known to play a key role in the regulation of eukaryotic phytoplankton population densities; however, little is known about the mechanisms of how they interact with their hosts and how phytoplankton populations mediate their regulations. Viruses are obligate parasites that depend on host cell machinery for their dissemination in the environment (most of the time through host cell lysis that liberates many new particles). But viruses also depend on a reliable host population to carry on their replication before losing their viability. How do hosts cells survive when they coexist with their viruses? We show that clonal lines of three picoeukaryotic green algae (i.e. Bathycoccus sp., Micromonas sp., Ostreococcus tauri) reproducibly acquire resistance to their specific viruses following a round of infection. Our observations show that two mechanisms of resistance may operate in O. tauri. In the first resistant type, viruses can attach to their host cells but no new particles develop. In the second one, O. tauri acquires tolerance to its virus and releases these viruses consistently. These lines maintained their resistance over a 3-year period, irrespective of whether or not they were re-challenged with new viral inoculations. Co-culturing resistant and susceptible lines revealed resistance to be associated with reduced host fitness in terms of growth rate.
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Affiliation(s)
- Rozenn Thomas
- UPMC Univ Paris 06 CNRS, FRE 3355, Observatoire Océanologique, 66650, Banyuls-sur-Mer, France
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Dittmar T, Zänker KS. Horizontal gene transfers with or without cell fusions in all categories of the living matter. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2011; 714:5-89. [PMID: 21506007 PMCID: PMC7120942 DOI: 10.1007/978-94-007-0782-5_2] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
This article reviews the history of widespread exchanges of genetic segments initiated over 3 billion years ago, to be part of their life style, by sphero-protoplastic cells, the ancestors of archaea, prokaryota, and eukaryota. These primordial cells shared a hostile anaerobic and overheated environment and competed for survival. "Coexist with, or subdue and conquer, expropriate its most useful possessions, or symbiose with it, your competitor" remain cellular life's basic rules. This author emphasizes the role of viruses, both in mediating cell fusions, such as the formation of the first eukaryotic cell(s) from a united crenarchaeon and prokaryota, and the transfer of host cell genes integrated into viral (phages) genomes. After rising above the Darwinian threshold, rigid rules of speciation and vertical inheritance in the three domains of life were established, but horizontal gene transfers with or without cell fusions were never abolished. The author proves with extensive, yet highly selective documentation, that not only unicellular microorganisms, but the most complex multicellular entities of the highest ranks resort to, and practice, cell fusions, and donate and accept horizontally (laterally) transferred genes. Cell fusions and horizontally exchanged genetic materials remain the fundamental attributes and inherent characteristics of the living matter, whether occurring accidentally or sought after intentionally. These events occur to cells stagnating for some 3 milliard years at a lower yet amazingly sophisticated level of evolution, and to cells achieving the highest degree of differentiation, and thus functioning in dependence on the support of a most advanced multicellular host, like those of the human brain. No living cell is completely exempt from gene drains or gene insertions.
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Affiliation(s)
- Thomas Dittmar
- Inst. Immunologie, Universität Witten/Herdecke, Stockumer Str. 10, Witten, 58448 Germany
| | - Kurt S. Zänker
- Institute of Immunologie, University of Witten/Herdecke, Stockumer Str. 10, Witten, 58448 Germany
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11
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Lomas MW, Bronk DA, van den Engh G. Use of flow cytometry to measure biogeochemical rates and processes in the ocean. ANNUAL REVIEW OF MARINE SCIENCE 2011; 3:537-566. [PMID: 21329216 DOI: 10.1146/annurev-marine-120709-142834] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
An important goal of marine biogeochemists is to quantify the rates at which elements cycle through the ocean's diverse microbial assemblage, as well as to determine how these rates vary in time and space. The traditional view that phytoplankton are producers and bacteria are consumers has been found to be overly simplistic, and environmental metagenomics is discovering new and important microbial metabolisms at an accelerating rate. Many nutritional strategies previously attributed to one microorganism or functional group are also or instead carried out by other groups. To tease apart which organism is doing what will require new analytical approaches. Flow cytometry, when combined with other techniques, has great potential for expanding our understanding of microbial interactions because groups can be distinguished optically, sorted, and then collected for subsequent analyses. Herein, we review the advances in our understanding of marine biogeochemistry that have arisen from the use of flow cytometry.
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Affiliation(s)
- Michael W Lomas
- Bermuda Institute of Ocean Sciences, Ferry Reach, St. George's GE01, Bermuda.
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12
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Tomaru Y, Mizumoto H, Nagasaki K. Virus resistance in the toxic bloom-forming dinoflagellate Heterocapsa circularisquama to single-stranded RNA virus infection. Environ Microbiol 2009; 11:2915-23. [PMID: 19735281 DOI: 10.1111/j.1462-2920.2009.02047.x] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
HcRNAV is the only known cultured dinoflagellate-infecting RNA virus. Lysis of its host dinoflagellate Heterocapsa circularisquama caused by HcRNAV is followed by apparent cell regrowth. Here we investigate the mechanism supporting the survival phenomenon. The proportion of normal cells with intact nucleus decreased to approximately 8% by 3 days post infection, and then, increased to > 90% at 15 days post infection. There were abnormal cells lacking an intact nucleus, and this was followed by propagation of virus-resistant survivor cells. The proportion of HcRNAV-resistant cells in three different subcultures and temporal fluctuations were compared: a clonal H. circularisquama culture without virus inoculation (virus-sensitive, VS), a surviving isolate from the HcRNAV-inoculated Culture-VS incubated in autoclaved medium (virus-resistant, VR) and a portion of Culture-VR incubated with HcRNAV (VR incubated with virus, VR + V). The proportion of HcRNAV-resistant cells in Culture-VS was 0% and in Culture-VR + V was > 94% during the experiment; and Culture-VR fluctuated from 4% to 71%. Hence, the virus resistance was assumed to be reversible. Using Northern hybridization, viral genome accumulation was not detected in Culture-VR + V cells either inoculated with HcRNAV or transfected with HcRNAV-genome; thus, intracellular viral RNA replication was assumed to be interrupted in the virus-resistant cells.
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Affiliation(s)
- Yuji Tomaru
- National Research Institute of Fisheries and Environment of Inland Sea, 2-17-5 Maruishi, Hatsukaichi, Hiroshima 739-0452, Japan.
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13
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Nagasaki K, Tomaru Y. [Recent progress in protist virology--molecular ecology, taxonomy, molecular evolution]. Uirusu 2009; 59:31-36. [PMID: 19927986 DOI: 10.2222/jsv.59.31] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
At present, more than 40 protist-infecting viruses have been isolated and characterized. From the viewpoints of molecular ecology, taxomony and molecular evolution, several new discoveries were made within the last five years. In this minireview, three topics of interest on protist-infecting viruses are introduced: 1) molecular ecological relationships between a bloom-forming dinoflagellate Heterocapsa circularisquama and its ssRNA virus (HcRNAV); 2) findings of new ssRNA- and ssDNA-virus groups infecting diatoms; 3) establishment of a hypothesis concerning the evolution of picornaviruses. The potential of aquatic virus studies is far-reaching and inestimable.
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Affiliation(s)
- Keizo Nagasaki
- Natl. Res. Inst. Fish. Environ. Inland Sea, Fisheries Research Agency.
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14
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Abstract
Viruses are ubiquitous in the sea and appear to outnumber all other forms of marine life by at least an order of magnitude. Through selective infection, viruses influence nutrient cycling, community structure, and evolution in the ocean. Over the past 20 years we have learned a great deal about the diversity and ecology of the viruses that constitute the marine virioplankton, but until recently the emphasis has been on DNA viruses. Along with expanding knowledge about RNA viruses that infect important marine animals, recent isolations of RNA viruses that infect single-celled eukaryotes and molecular analyses of the RNA virioplankton have revealed that marine RNA viruses are novel, widespread, and genetically diverse. Discoveries in marine RNA virology are broadening our understanding of the biology, ecology, and evolution of viruses, and the epidemiology of viral diseases, but there is still much that we need to learn about the ecology and diversity of RNA viruses before we can fully appreciate their contributions to the dynamics of marine ecosystems. As a step toward making sense of how RNA viruses contribute to the extraordinary viral diversity in the sea, we summarize in this review what is currently known about RNA viruses that infect marine organisms.
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Affiliation(s)
- Andrew S Lang
- Department of Biology, Memorial University of Newfoundland, St John's, NL, Canada.
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