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Ha AD, Moniruzzaman M, Aylward FO. Assessing the biogeography of marine giant viruses in four oceanic transects. ISME COMMUNICATIONS 2023; 3:43. [PMID: 37120676 PMCID: PMC10148842 DOI: 10.1038/s43705-023-00252-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/28/2023] [Revised: 04/11/2023] [Accepted: 04/19/2023] [Indexed: 05/01/2023]
Abstract
Viruses of the phylum Nucleocytoviricota are ubiquitous in ocean waters and play important roles in shaping the dynamics of marine ecosystems. In this study, we leveraged the bioGEOTRACES metagenomic dataset collected across the Atlantic and Pacific Oceans to investigate the biogeography of these viruses in marine environments. We identified 330 viral genomes, including 212 in the order Imitervirales and 54 in the order Algavirales. We found that most viruses appeared to be prevalent in shallow waters (<150 m), and that viruses of the Mesomimiviridae (Imitervirales) and Prasinoviridae (Algavirales) are by far the most abundant and diverse groups in our survey. Five mesomimiviruses and one prasinovirus are particularly widespread in oligotrophic waters; annotation of these genomes revealed common stress response systems, photosynthesis-associated genes, and oxidative stress modulation genes that may be key to their broad distribution in the pelagic ocean. We identified a latitudinal pattern in viral diversity in one cruise that traversed the North and South Atlantic Ocean, with viral diversity peaking at high latitudes of the northern hemisphere. Community analyses revealed three distinct Nucleocytoviricota communities across latitudes, categorized by latitudinal distance towards the equator. Our results contribute to the understanding of the biogeography of these viruses in marine systems.
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Affiliation(s)
- Anh D Ha
- Department of Biological Sciences, Virginia Tech, 926 West Campus Drive, Blacksburg, VA, 24061, USA
| | - Mohammad Moniruzzaman
- Department of Marine Biology and Ecology, Rosenstiel School of Marine, Atmospheric, and Earth Science, University of Miami, 4600 Rickenbacker Causeway, Miami, FL, 33149, USA
| | - Frank O Aylward
- Department of Biological Sciences, Virginia Tech, 926 West Campus Drive, Blacksburg, VA, 24061, USA.
- Center for Emerging, Zoonotic, and Arthropod-Borne Infectious Disease, Virginia Tech, Blacksburg, VA, 24061, USA.
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2
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Ha AD, Moniruzzaman M, Aylward FO. Assessing the biogeography of marine giant viruses in four oceanic transects. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.01.30.526306. [PMID: 36778472 PMCID: PMC9915497 DOI: 10.1101/2023.01.30.526306] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Viruses of the phylum Nucleocytoviricota are ubiquitous in ocean waters and play important roles in shaping the dynamics of marine ecosystems. In this study, we leveraged the bioGEOTRACES metagenomic dataset collected across the Atlantic and Pacific Oceans to investigate the biogeography of these viruses in marine environments. We identified 330 viral genomes, including 212 in the order Imitervirales and 54 in the order Algavirales . We found that most viruses appeared to be prevalent in shallow waters (<150 meters), and that viruses of the Mesomimiviridae ( Imitervirales ) and Prasinoviridae ( Algavirales ) are by far the most abundant and diverse groups in our survey. Five mesomimiviruses and one prasinovirus are particularly widespread in oligotrophic waters; annotation of these genomes revealed common stress response systems, photosynthesis-associated genes, and oxidative stress modulation that may be key to their broad distribution in the pelagic ocean. We identified a latitudinal pattern in viral diversity in one cruise that traversed the North and South Atlantic Ocean, with viral diversity peaking at high latitudes of the northern hemisphere. Community analyses revealed three distinct Nucleocytoviricota communities across latitudes, categorized by latitudinal distance towards the equator. Our results contribute to the understanding of the biogeography of these viruses in marine systems.
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Affiliation(s)
- Anh D. Ha
- Department of Biological Sciences, Virginia Tech, Blacksburg VA, 24061
| | - Mohammad Moniruzzaman
- Rosenstiel School of Marine Atmospheric, and Earth Science, University of Miami, Coral Gables FL 33149
| | - Frank O. Aylward
- Department of Biological Sciences, Virginia Tech, Blacksburg VA, 24061
- Center for Emerging, Zoonotic, and Arthropod-Borne Infectious Disease, Virginia Tech, Blacksburg VA, 24061
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3
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Nelson DR, Hazzouri KM, Lauersen KJ, Jaiswal A, Chaiboonchoe A, Mystikou A, Fu W, Daakour S, Dohai B, Alzahmi A, Nobles D, Hurd M, Sexton J, Preston MJ, Blanchette J, Lomas MW, Amiri KMA, Salehi-Ashtiani K. Large-scale genome sequencing reveals the driving forces of viruses in microalgal evolution. Cell Host Microbe 2021; 29:250-266.e8. [PMID: 33434515 DOI: 10.1016/j.chom.2020.12.005] [Citation(s) in RCA: 25] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2020] [Revised: 10/08/2020] [Accepted: 11/18/2020] [Indexed: 01/08/2023]
Abstract
Being integral primary producers in diverse ecosystems, microalgal genomes could be mined for ecological insights, but representative genome sequences are lacking for many phyla. We cultured and sequenced 107 microalgae species from 11 different phyla indigenous to varied geographies and climates. This collection was used to resolve genomic differences between saltwater and freshwater microalgae. Freshwater species showed domain-centric ontology enrichment for nuclear and nuclear membrane functions, while saltwater species were enriched in organellar and cellular membrane functions. Further, marine species contained significantly more viral families in their genomes (p = 8e-4). Sequences from Chlorovirus, Coccolithovirus, Pandoravirus, Marseillevirus, Tupanvirus, and other viruses were found integrated into the genomes of algal from marine environments. These viral-origin sequences were found to be expressed and code for a wide variety of functions. Together, this study comprehensively defines the expanse of protein-coding and viral elements in microalgal genomes and posits a unified adaptive strategy for algal halotolerance.
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Affiliation(s)
- David R Nelson
- Center for Genomics and Systems Biology, New York University Abu Dhabi, Abu Dhabi, UAE.
| | - Khaled M Hazzouri
- Khalifa Center for Genetic Engineering and Biotechnology (KCGEB), UAE University, Al Ain, Abu Dhabi, UAE; Biology Department, College of Science, UAE University, Al Ain, Abu Dhabi, UAE
| | - Kyle J Lauersen
- Biological and Environmental Sciences and Engineering Division, King Abdullah University of Science and Technology (KAUST), Thuwal, Kingdom of Saudi Arabia
| | - Ashish Jaiswal
- Division of Science and Math, New York University Abu Dhabi, Abu Dhabi, UAE
| | | | - Alexandra Mystikou
- Center for Genomics and Systems Biology, New York University Abu Dhabi, Abu Dhabi, UAE
| | - Weiqi Fu
- Division of Science and Math, New York University Abu Dhabi, Abu Dhabi, UAE
| | - Sarah Daakour
- Center for Genomics and Systems Biology, New York University Abu Dhabi, Abu Dhabi, UAE
| | - Bushra Dohai
- Division of Science and Math, New York University Abu Dhabi, Abu Dhabi, UAE
| | - Amnah Alzahmi
- Center for Genomics and Systems Biology, New York University Abu Dhabi, Abu Dhabi, UAE
| | - David Nobles
- UTEX Culture Collection of Algae at the University of Texas at Austin, Austin, TX, USA
| | - Mark Hurd
- National Center for Marine Algae and Microbiota, East Boothbay, ME, USA
| | - Julie Sexton
- National Center for Marine Algae and Microbiota, East Boothbay, ME, USA
| | - Michael J Preston
- National Center for Marine Algae and Microbiota, East Boothbay, ME, USA
| | - Joan Blanchette
- National Center for Marine Algae and Microbiota, East Boothbay, ME, USA
| | - Michael W Lomas
- National Center for Marine Algae and Microbiota, East Boothbay, ME, USA
| | - Khaled M A Amiri
- Khalifa Center for Genetic Engineering and Biotechnology (KCGEB), UAE University, Al Ain, Abu Dhabi, UAE; Biology Department, College of Science, UAE University, Al Ain, Abu Dhabi, UAE
| | - Kourosh Salehi-Ashtiani
- Center for Genomics and Systems Biology, New York University Abu Dhabi, Abu Dhabi, UAE; Division of Science and Math, New York University Abu Dhabi, Abu Dhabi, UAE.
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4
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Chelkha N, Levasseur A, La Scola B, Colson P. Host-virus interactions and defense mechanisms for giant viruses. Ann N Y Acad Sci 2020; 1486:39-57. [PMID: 33090482 DOI: 10.1111/nyas.14469] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2020] [Revised: 06/28/2020] [Accepted: 07/26/2020] [Indexed: 12/26/2022]
Abstract
Giant viruses, with virions larger than 200 nm and genomes larger than 340 kilobase pairs, modified the now outdated perception of the virosphere. With virions now reported reaching up to 1.5 μm in size and genomes of up to 2.5 Mb encoding components shared with cellular life forms, giant viruses exhibit a complexity similar to microbes, such as bacteria and archaea. Here, we review interactions of giant viruses with their hosts and defense strategies of giant viruses against their hosts and coinfecting microorganisms or virophages. We also searched by comparative genomics for homologies with proteins described or suspected to be involved in defense mechanisms. Our search reveals that natural immunity and apoptosis seem to be crucial components of the host defense against giant virus infection. Conversely, giant viruses possess methods of hijacking host functions to counteract cellular antiviral responses. In addition, giant viruses may encode other unique and complex pathways to manipulate the host machinery and eliminate other competing microorganisms. Notably, giant viruses have evolved defense mechanisms against their virophages and they might trigger defense systems against other viruses through sequence integration. We anticipate that comparative genomics may help identifying genes involved in defense strategies of both giant viruses and their hosts.
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Affiliation(s)
- Nisrine Chelkha
- Aix-Marseille University, Institut de Recherche pour le Développement (IRD), Assistance Publique - Hôpitaux de Marseille (AP-HM), Microbes Evolution Phylogeny and Infections (MEPHI), Marseille, France
| | - Anthony Levasseur
- Aix-Marseille University, Institut de Recherche pour le Développement (IRD), Assistance Publique - Hôpitaux de Marseille (AP-HM), Microbes Evolution Phylogeny and Infections (MEPHI), Marseille, France
- IHU Méditerranée Infection, Marseille, France
| | - Bernard La Scola
- Aix-Marseille University, Institut de Recherche pour le Développement (IRD), Assistance Publique - Hôpitaux de Marseille (AP-HM), Microbes Evolution Phylogeny and Infections (MEPHI), Marseille, France
- IHU Méditerranée Infection, Marseille, France
| | - Philippe Colson
- Aix-Marseille University, Institut de Recherche pour le Développement (IRD), Assistance Publique - Hôpitaux de Marseille (AP-HM), Microbes Evolution Phylogeny and Infections (MEPHI), Marseille, France
- IHU Méditerranée Infection, Marseille, France
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5
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Nissimov JI, Talmy D, Haramaty L, Fredricks HF, Zelzion E, Knowles B, Eren AM, Vandzura R, Laber CP, Schieler BM, Johns CT, More KD, Coolen MJL, Follows MJ, Bhattacharya D, Van Mooy BAS, Bidle KD. Biochemical diversity of glycosphingolipid biosynthesis as a driver of Coccolithovirus competitive ecology. Environ Microbiol 2019; 21:2182-2197. [PMID: 31001863 DOI: 10.1111/1462-2920.14633] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2019] [Accepted: 04/15/2019] [Indexed: 11/29/2022]
Abstract
Coccolithoviruses (EhVs) are large, double-stranded DNA-containing viruses that infect the single-celled, marine coccolithophore Emiliania huxleyi. Given the cosmopolitan nature and global importance of E. huxleyi as a bloom-forming, calcifying, photoautotroph, E. huxleyi-EhV interactions play a key role in oceanic carbon biogeochemistry. Virally-encoded glycosphingolipids (vGSLs) are virulence factors that are produced by the activity of virus-encoded serine palmitoyltransferase (SPT). Here, we characterize the dynamics, diversity and catalytic production of vGSLs in an array of EhV strains in relation to their SPT sequence composition and explore the hypothesis that they are a determinant of infectivity and host demise. vGSL production and diversity was positively correlated with increased virulence, virus replication rate and lytic infection dynamics in laboratory experiments, but they do not explain the success of less-virulent EhVs in natural EhV communities. The majority of EhV-derived SPT amplicon sequences associated with infected cells in the North Atlantic derived from slower infecting, less virulent EhVs. Our lab-, field- and mathematical model-based data and simulations support ecological scenarios whereby slow-infecting, less-virulent EhVs successfully compete in North Atlantic populations of E. huxleyi, through either the preferential removal of fast-infecting, virulent EhVs during active infection or by having access to a broader host range.
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Affiliation(s)
- Jozef I Nissimov
- Department of Marine and Coastal Sciences, Rutgers University, New Brunswick, NJ, 08901, USA.,Scottish Association for Marine Science, Scottish Marine Institute, Oban, Argyll, PA37 1QA, Scotland, UK
| | - David Talmy
- Department of Microbiology, University of Tennessee-Knoxville, Knoxville, TN, 37996, USA
| | - Liti Haramaty
- Department of Marine and Coastal Sciences, Rutgers University, New Brunswick, NJ, 08901, USA
| | - Helen F Fredricks
- Department of Marine Chemistry and Geochemistry, Woods Hole Oceanographic Institution, Woods Hole, MA, 02543, USA
| | - Ehud Zelzion
- Department of Biochemistry and Microbiology, Rutgers University, New Brunswick, NJ, 08901, USA
| | - Ben Knowles
- Department of Marine and Coastal Sciences, Rutgers University, New Brunswick, NJ, 08901, USA
| | - A Murat Eren
- Marine Biological Laboratory, Josephine Bay Paul Center, Woods Hole, Massachusetts, 02543, USA.,Department of Medicine, The University of Chicago, Chicago, IL, 60637, USA
| | - Rebecca Vandzura
- Department of Marine and Coastal Sciences, Rutgers University, New Brunswick, NJ, 08901, USA
| | - Christien P Laber
- Department of Marine and Coastal Sciences, Rutgers University, New Brunswick, NJ, 08901, USA
| | - Brittany M Schieler
- Department of Marine and Coastal Sciences, Rutgers University, New Brunswick, NJ, 08901, USA
| | - Christopher T Johns
- Department of Marine and Coastal Sciences, Rutgers University, New Brunswick, NJ, 08901, USA
| | - Kuldeep D More
- WA-Organic and Isotope Geochemistry Centre, School of Earth and Planetary Sciences, Curtin University, Bentley, WA, 6102, Australia
| | - Marco J L Coolen
- WA-Organic and Isotope Geochemistry Centre, School of Earth and Planetary Sciences, Curtin University, Bentley, WA, 6102, Australia
| | - Michael J Follows
- Department of Earth, Atmosphere and Planetary Sciences, Massachusetts Institute of Technology, Cambridge, MA, 02139, USA
| | - Debashish Bhattacharya
- Department of Biochemistry and Microbiology, Rutgers University, New Brunswick, NJ, 08901, USA
| | - Benjamin A S Van Mooy
- Department of Marine Chemistry and Geochemistry, Woods Hole Oceanographic Institution, Woods Hole, MA, 02543, USA
| | - Kay D Bidle
- Department of Marine and Coastal Sciences, Rutgers University, New Brunswick, NJ, 08901, USA
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6
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Emerging Interaction Patterns in the Emiliania huxleyi-EhV System. Viruses 2017; 9:v9030061. [PMID: 28327527 PMCID: PMC5371816 DOI: 10.3390/v9030061] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2017] [Revised: 03/15/2017] [Accepted: 03/16/2017] [Indexed: 01/25/2023] Open
Abstract
Viruses are thought to be fundamental in driving microbial diversity in the oceanic planktonic realm. That role and associated emerging infection patterns remain particularly elusive for eukaryotic phytoplankton and their viruses. Here we used a vast number of strains from the model system Emiliania huxleyi/Emiliania huxleyi Virus to quantify parameters such as growth rate (µ), resistance (R), and viral production (Vp) capacities. Algal and viral abundances were monitored by flow cytometry during 72-h incubation experiments. The results pointed out higher viral production capacity in generalist EhV strains, and the virus-host infection network showed a strong co-evolution pattern between E. huxleyi and EhV populations. The existence of a trade-off between resistance and growth capacities was not confirmed.
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7
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Highfield A, Joint I, Gilbert JA, Crawfurd KJ, Schroeder DC. Change in Emiliania huxleyi Virus Assemblage Diversity but Not in Host Genetic Composition during an Ocean Acidification Mesocosm Experiment. Viruses 2017; 9:v9030041. [PMID: 28282890 PMCID: PMC5371796 DOI: 10.3390/v9030041] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2017] [Revised: 02/23/2017] [Accepted: 03/02/2017] [Indexed: 11/16/2022] Open
Abstract
Effects of elevated pCO₂ on Emiliania huxleyi genetic diversity and the viruses that infect E. huxleyi (EhVs) have been investigated in large volume enclosures in a Norwegian fjord. Triplicate enclosures were bubbled with air enriched with CO₂ to 760 ppmv whilst the other three enclosures were bubbled with air at ambient pCO₂; phytoplankton growth was initiated by the addition of nitrate and phosphate. E. huxleyi was the dominant coccolithophore in all enclosures, but no difference in genetic diversity, based on DGGE analysis using primers specific to the calcium binding protein gene (gpa) were detected in any of the treatments. Chlorophyll concentrations and primary production were lower in the three elevated pCO₂ treatments than in the ambient treatments. However, although coccolithophores numbers were reduced in two of the high-pCO₂ treatments; in the third, there was no suppression of coccolithophores numbers, which were very similar to the three ambient treatments. In contrast, there was considerable variation in genetic diversity in the EhVs, as determined by analysis of the major capsid protein (mcp) gene. EhV diversity was much lower in the high-pCO₂ treatment enclosure that did not show inhibition of E. huxleyi growth. Since virus infection is generally implicated as a major factor in terminating phytoplankton blooms, it is suggested that no study of the effect of ocean acidification in phytoplankton can be complete if it does not include an assessment of viruses.
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Affiliation(s)
- Andrea Highfield
- The Marine Biological Association, The Laboratory, Citadel Hill, Plymouth PL1 2PB, UK.
| | - Ian Joint
- The Marine Biological Association, The Laboratory, Citadel Hill, Plymouth PL1 2PB, UK.
| | - Jack A Gilbert
- The Microbiome Centre, Department of Surgery, University of Chicago, Chicago, IL 60637, USA.
- Division of Bioscience, Argonne National Laboratory, 9700 South Cass Avenue, Argonne, IL 60439, USA.
| | - Katharine J Crawfurd
- Department of Biological Oceanography, NIOZ-Royal Netherlands Institute for Sea Research, P.O. Box 59, 1790 AB Den Burg, Texel, The Netherlands.
| | - Declan C Schroeder
- The Marine Biological Association, The Laboratory, Citadel Hill, Plymouth PL1 2PB, UK.
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8
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Nissimov JI, Napier JA, Allen MJ, Kimmance SA. Intragenus competition between coccolithoviruses: an insight on how a select few can come to dominate many. Environ Microbiol 2015; 18:133-45. [PMID: 25970076 DOI: 10.1111/1462-2920.12902] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2014] [Revised: 03/20/2015] [Accepted: 05/04/2015] [Indexed: 11/27/2022]
Abstract
Viruses are a major cause of coccolithophore bloom demise in both temperate and sub-temperate oceanic regions. Most infection studies on coccolithoviruses have been conducted with a single virus strain, and the effect of intragenus competition by closely related coccolithoviruses has been ignored. Here we conducted combined infection experiments, infecting Emiliania huxleyi CCMP 2090 with two coccolithoviruses: EhV-86 and EhV-207 both simultaneously and independently. EhV-207 displayed a shorter lytic cycle and increased production potential than EhV-86 and was remarkably superior under competitive conditions. Although the viruses displayed identical adsorption kinetics in the first 2 h post infection, EhV-207 gained a numerical advantage as early as 8 h post infection. Quantitative polymerase chain reaction (PCR) revealed that when infecting in combination, EhV-207 was not affected by the presence of EhV-86, whereas EhV-86 was quickly out-competed, and a significant reduction in free and cell-associated EhV-86 was seen as early as 2 days after the initial infection. The observation of such clear phenotypic differences between genetically distinct, yet similar, coccolithovirus strains, by flow cytometry and quantitative real-time PCR allowed tentative links to the burgeoning genomic, transcriptomic and metabolic data to be made and the factors driving their selection, in particular to the de novo coccolithovirus-encoded sphingolipid biosynthesis pathway. This work illustrates that, even within a family, not all viruses are created equally, and the potential exists for relatively small genetic changes to infer disproportionately large competitive advantages for one coccolithovirus over another, ultimately leading to a few viruses dominating the many.
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Affiliation(s)
- Jozef I Nissimov
- Plymouth Marine Laboratory, Prospect Place, The Hoe, Plymouth, PL1 3DH, UK
| | - Johnathan A Napier
- Department of Biological Chemistry, Rothamsted Research, Harpenden, Herts, AL5 2JQ, UK
| | - Michael J Allen
- Plymouth Marine Laboratory, Prospect Place, The Hoe, Plymouth, PL1 3DH, UK
| | - Susan A Kimmance
- Plymouth Marine Laboratory, Prospect Place, The Hoe, Plymouth, PL1 3DH, UK
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9
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How many Coccolithovirus genotypes does it take to terminate an Emiliania huxleyi bloom? Virology 2014; 466-467:138-45. [DOI: 10.1016/j.virol.2014.07.017] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2014] [Revised: 07/08/2014] [Accepted: 07/11/2014] [Indexed: 11/22/2022]
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10
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Pagarete A, Kusonmano K, Petersen K, Kimmance SA, Martínez Martínez J, Wilson WH, Hehemann JH, Allen MJ, Sandaa RA. Dip in the gene pool: metagenomic survey of natural coccolithovirus communities. Virology 2014; 466-467:129-37. [PMID: 24947907 DOI: 10.1016/j.virol.2014.05.020] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2014] [Revised: 04/23/2014] [Accepted: 05/18/2014] [Indexed: 11/30/2022]
Abstract
Despite the global oceanic distribution and recognised biogeochemical impact of coccolithoviruses (EhV), their diversity remains poorly understood. Here we employed a metagenomic approach to study the occurrence and progression of natural EhV community genomic variability. Analysis of EhV metagenomes from the early and late stages of an induced bloom led to three main discoveries. First, we observed resilient and specific genomic signatures in the EhV community associated with the Norwegian coast, which reinforce the existence of limitations to the capacity of dispersal and genomic exchange among EhV populations. Second, we identified a hyper-variable region (approximately 21kbp long) in the coccolithovirus genome. Third, we observed a clear trend for EhV relative amino-acid diversity to reduce from early to late stages of the bloom. This study validated two new methodological combinations, and proved very useful in the discovery of new genomic features associated with coccolithovirus natural communities.
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Affiliation(s)
| | | | - Kjell Petersen
- Computational Biology Unit, University of Bergen, Norway
| | | | | | - William H Wilson
- Plymouth Marine Laboratory, Plymouth, UK; Bigelow Laboratory for Ocean Sciences, East Boothbay, ME, USA
| | - Jan-Hendrik Hehemann
- Department of Civil & Environmental Engineering, Massachusetts Institute of Technology, USA
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11
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Vardi A, Haramaty L, Van Mooy BAS, Fredricks HF, Kimmance SA, Larsen A, Bidle KD. Host-virus dynamics and subcellular controls of cell fate in a natural coccolithophore population. Proc Natl Acad Sci U S A 2012; 109:19327-32. [PMID: 23134731 PMCID: PMC3511156 DOI: 10.1073/pnas.1208895109] [Citation(s) in RCA: 150] [Impact Index Per Article: 12.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Marine viruses are major evolutionary and biogeochemical drivers in marine microbial foodwebs. However, an in-depth understanding of the cellular mechanisms and the signal transduction pathways mediating host-virus interactions during natural bloom dynamics has remained elusive. We used field-based mesocosms to examine the "arms race" between natural populations of the coccolithophore Emiliania huxleyi and its double-stranded DNA-containing coccolithoviruses (EhVs). Specifically, we examined the dynamics of EhV infection and its regulation of cell fate over the course of bloom development and demise using a diverse suite of molecular tools and in situ fluorescent staining to target different levels of subcellular resolution. We demonstrate the concomitant induction of reactive oxygen species, caspase-specific activity, metacaspase expression, and programmed cell death in response to the accumulation of virus-derived glycosphingolipids upon infection of natural E. huxleyi populations. These subcellular responses to viral infection simultaneously resulted in the enhanced production of transparent exopolymer particles, which can facilitate aggregation and stimulate carbon flux. Our results not only corroborate the critical role for glycosphingolipids and programmed cell death in regulating E. huxleyi-EhV interactions, but also elucidate promising molecular biomarkers and lipid-based proxies for phytoplankton host-virus interactions in natural systems.
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Affiliation(s)
- Assaf Vardi
- Environmental Biophysics and Molecular Ecology Group, Institute of Marine and Coastal Sciences, Rutgers University, New Brunswick, NJ 08901
| | - Liti Haramaty
- Environmental Biophysics and Molecular Ecology Group, Institute of Marine and Coastal Sciences, Rutgers University, New Brunswick, NJ 08901
| | - Benjamin A. S. Van Mooy
- Department of Marine Chemistry and Geochemistry, Woods Hole Oceanographic Institution, Woods Hole, MA 02543
| | - Helen F. Fredricks
- Department of Marine Chemistry and Geochemistry, Woods Hole Oceanographic Institution, Woods Hole, MA 02543
| | - Susan A. Kimmance
- Plymouth Marine Laboratory, The Hoe, Plymouth PL1 3DH, United Kingdom; and
| | - Aud Larsen
- Uni Environment, Uni Research, NO-5020 Bergen, Norway
| | - Kay D. Bidle
- Environmental Biophysics and Molecular Ecology Group, Institute of Marine and Coastal Sciences, Rutgers University, New Brunswick, NJ 08901
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12
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Gledhill M, Devez A, Highfield A, Singleton C, Achterberg EP, Schroeder D. Effect of Metals on the Lytic Cycle of the Coccolithovirus, EhV86. Front Microbiol 2012; 3:155. [PMID: 22536202 PMCID: PMC3333479 DOI: 10.3389/fmicb.2012.00155] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2011] [Accepted: 04/04/2012] [Indexed: 01/30/2023] Open
Abstract
In this study we show that metals, and in particular copper (Cu), can disrupt the lytic cycle in the Emiliania huxleyi - EhV86 host-virus system. E. huxleyi lysis rates were reduced at high total Cu concentrations (> approximately 500 nM) in the presence and absence of EDTA (ethylenediaminetetraacetic acid) in acute short term exposure experiments. Zinc (Zn), cadmium (Cd), and cobalt (Co) were not observed to affect the lysis rate of EhV86 in these experiments. The cellular glutathione (GSH) content increased in virus infected cells, but not as a result of metal exposure. In contrast, the cellular content of phytochelatins (PCs) increased only in response to metal exposure. The increase in glutathione content is consistent with increases in the production of reactive oxygen species (ROS) on viral lysis, while increases in PC content are likely linked to metal homeostasis and indicate that metal toxicity to the host was not affected by viral infection. We propose that Cu prevents lytic production of EhV86 by interfering with virus DNA (deoxyribonucleic acid) synthesis through a transcriptional block, which ultimately suppresses the formation of ROS.
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Affiliation(s)
- Martha Gledhill
- School of Ocean and Earth Science, University of Southampton, National Oceanography CentreSouthampton, UK
| | - Aurélie Devez
- School of Ocean and Earth Science, University of Southampton, National Oceanography CentreSouthampton, UK
| | - Andrea Highfield
- Marine Biological Association of the UKCitadel Hill, Plymouth, UK
| | - Chloe Singleton
- Marine Biological Association of the UKCitadel Hill, Plymouth, UK
| | - Eric P. Achterberg
- School of Ocean and Earth Science, University of Southampton, National Oceanography CentreSouthampton, UK
| | - Declan Schroeder
- Marine Biological Association of the UKCitadel Hill, Plymouth, UK
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Martínez JM, Schroeder DC, Wilson WH. Dynamics and genotypic composition of Emiliania huxleyi and their co-occurring viruses during a coccolithophore bloom in the North Sea. FEMS Microbiol Ecol 2012; 81:315-23. [PMID: 22404582 DOI: 10.1111/j.1574-6941.2012.01349.x] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2011] [Revised: 12/19/2011] [Accepted: 02/23/2012] [Indexed: 11/30/2022] Open
Abstract
We studied the temporal succession of vertical profiles of Emiliania huxleyi and their specific viruses (EhVs) during the progression of a natural phytoplankton bloom in the North Sea in June 1999. Genotypic richness was assessed by exploiting the variations in a gene encoding a protein with calcium-binding motifs (GPA) for E. huxleyi and in the viral major capsid protein gene for EhVs. Using denaturing gradient gel electrophoresis and sequencing analysis, we showed at least three different E. huxleyi and EhV genotypic profiles during the period of study, revealing a complex, and changing assemblage at the molecular level. Our results also indicate that the dynamics of EhV genotypes reflect fluctuations in abundance of potential E. huxleyi host cells. The presence and concentration of specific EhVs in the area prior to the bloom, or EhVs transported into the area by different water masses, are significant factors affecting the structure and intraspecific succession of E. huxleyi during the phytoplankton bloom.
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Abstract
Because viruses of eukaryotic algae are incredibly diverse, sweeping generalizations about their ecology are rare. These obligate parasites infect a range of algae and their diversity can be illustrated by considering that isolates range from small particles with ssRNA genomes to much larger particles with 560 kb dsDNA genomes. Molecular research has also provided clues about the extent of their diversity especially considering that genetic signatures of algal viruses in the environment rarely match cultivated viruses. One general concept in algal virus ecology that has emerged is that algal viruses are very host specific and most infect only certain strains of their hosts; with the exception of viruses of brown algae, evidence for interspecies infectivity is lacking. Although some host-virus systems behave with boom-bust oscillations, complex patterns of intraspecies infectivity can lead to host-virus coexistence obfuscating the role of viruses in host population dynamics. Within the framework of population dynamics, host density dependence is an important phenomenon that influences virus abundances in nature. Variable burst sizes of different viruses also influence their abundances and permit speculations about different life strategies, but as exceptions are common in algal virus ecology, life strategy generalizations may not be broadly applicable. Gaps in knowledge of virus seasonality and persistence are beginning to close and investigations of environmental reservoirs and virus resilience may answer questions about virus inter-annual recurrences. Studies of algal mortality have shown that viruses are often important agents of mortality reinforcing notions about their ecological relevance, while observations of the surprising ways viruses interact with their hosts highlight the immaturity of our understanding. Considering that just two decades ago algal viruses were hardly acknowledged, recent progress affords the optimistic perspective that future studies will provide keys to unlocking our understanding of algal virus ecology specifically, and aquatic ecosystems generally.
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Affiliation(s)
- Steven M Short
- Department of Biology, University of Toronto Mississauga, Mississauga, Canada.
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Pagarete A, Corguillé G, Tiwari B, Ogata H, Vargas C, Wilson WH, Allen MJ. Unveiling the transcriptional features associated with coccolithovirus infection of natural Emiliania huxleyi blooms. FEMS Microbiol Ecol 2011; 78:555-64. [PMID: 22066669 DOI: 10.1111/j.1574-6941.2011.01191.x] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2011] [Revised: 08/01/2011] [Accepted: 08/12/2011] [Indexed: 11/27/2022] Open
Affiliation(s)
| | - Gildas Corguillé
- CNRS/UMPC, FR2424; Service Informatique et Génomique; Station Biologique; Roscoff; France
| | - Bela Tiwari
- NERC Environmental Bioinformatics Centre; Centre for Ecology and Hydrology; Wallingford; UK
| | - Hiroyuki Ogata
- Structural and Genomic Information Laboratory; CNRS-UPR2589; Mediterranean Institute of Microbiology (IFR-88); Aix-Marseille University; Marseille; France
| | - Colomban Vargas
- Equipe EPPO-Evolution du Plancton et PaléoOcéans; CNRS-UMR7144; Université Pierre et Marie Curie; Station Biologique; Roscoff; France
| | - William H. Wilson
- Bigelow Laboratory for Ocean Sciences; West Boothbay Harbor; ME; USA
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