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Foresi N, De Marco MA, Del Castello F, Ramirez L, Nejamkin A, Calo G, Grimsley N, Correa-Aragunde N, Martínez-Noël GMA. The tiny giant of the sea, Ostreococcus's unique adaptations. PLANT PHYSIOLOGY AND BIOCHEMISTRY : PPB 2024; 211:108661. [PMID: 38735153 DOI: 10.1016/j.plaphy.2024.108661] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/17/2023] [Revised: 04/14/2024] [Accepted: 04/23/2024] [Indexed: 05/14/2024]
Abstract
Ostreococcus spp. are unicellular organisms with one of the simplest cellular organizations. The sequencing of the genomes of different Ostreococcus species has reinforced this status since Ostreococcus tauri has one most compact nuclear genomes among eukaryotic organisms. Despite this, it has retained a number of genes, setting it apart from other organisms with similar small genomes. Ostreococcus spp. feature a substantial number of selenocysteine-containing proteins, which, due to their higher catalytic activity compared to their selenium-lacking counterparts, may require a reduced quantity of proteins. Notably, O. tauri encodes several ammonium transporter genes, that may provide it with a competitive edge for acquiring nitrogen (N). This characteristic makes it an intriguing model for studying the efficient use of N in eukaryotes. Under conditions of low N availability, O. tauri utilizes N from abundant proteins or amino acids, such as L-arginine, similar to higher plants. However, the presence of a nitric oxide synthase (L-arg substrate) sheds light on a new metabolic pathway for L-arg in algae. The metabolic adaptations of O. tauri to day and night cycles offer valuable insights into carbon and iron metabolic configuration. O. tauri has evolved novel strategies to optimize iron uptake, lacking the classic components of the iron absorption mechanism. Overall, the cellular and genetic characteristics of Ostreococcus contribute to its evolutionary success, making it an excellent model for studying the physiological and genetic aspects of how green algae have adapted to the marine environment. Furthermore, given its potential for lipid accumulation and its marine habitat, it may represent a promising avenue for third-generation biofuels.
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Affiliation(s)
- Noelia Foresi
- Instituto de Investigaciones Biológicas-UNMdP-CONICET, Mar del Plata, Argentina.
| | - María Agustina De Marco
- Instituto de Investigaciones en Biodiversidad y Biotecnología (INBIOTEC)-CONICET-FIBA, Mar del Plata, Argentina
| | | | - Leonor Ramirez
- Department of Plant Physiology, Umeå Plant Science Centre, Umeå University, SE-901 87, Umeå, Sweden
| | - Andres Nejamkin
- Instituto de Investigaciones Biológicas-UNMdP-CONICET, Mar del Plata, Argentina
| | - Gonzalo Calo
- Instituto de Investigaciones en Biodiversidad y Biotecnología (INBIOTEC)-CONICET-FIBA, Mar del Plata, Argentina
| | - Nigel Grimsley
- CNRS, LBBM, Sorbonne Université OOB, 1 Avenue de Pierre Fabre, 66650, Banyuls-sur-Mer, France
| | | | - Giselle M A Martínez-Noël
- Instituto de Investigaciones en Biodiversidad y Biotecnología (INBIOTEC)-CONICET-FIBA, Mar del Plata, Argentina.
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2
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Cho A, Lax G, Livingston SJ, Masukagami Y, Naumova M, Millar O, Husnik F, Keeling PJ. Genomic analyses of Symbiomonas scintillans show no evidence for endosymbiotic bacteria but does reveal the presence of giant viruses. PLoS Genet 2024; 20:e1011218. [PMID: 38557755 PMCID: PMC11008856 DOI: 10.1371/journal.pgen.1011218] [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: 12/04/2023] [Revised: 04/11/2024] [Accepted: 03/11/2024] [Indexed: 04/04/2024] Open
Abstract
Symbiomonas scintillans Guillou et Chrétiennot-Dinet, 1999 is a tiny (1.4 μm) heterotrophic microbial eukaryote. The genus was named based on the presence of endosymbiotic bacteria in its endoplasmic reticulum, however, like most such endosymbionts neither the identity nor functional association with its host were known. We generated both amplification-free shotgun metagenomics and whole genome amplification sequencing data from S. scintillans strains RCC257 and RCC24, but were unable to detect any sequences from known lineages of endosymbiotic bacteria. The absence of endobacteria was further verified with FISH analyses. Instead, numerous contigs in assemblies from both RCC24 and RCC257 were closely related to prasinoviruses infecting the green algae Ostreococcus lucimarinus, Bathycoccus prasinos, and Micromonas pusilla (OlV, BpV, and MpV, respectively). Using the BpV genome as a reference, we assembled a near-complete 190 kbp draft genome encoding all hallmark prasinovirus genes, as well as two additional incomplete assemblies of closely related but distinct viruses from RCC257, and three similar draft viral genomes from RCC24, which we collectively call SsVs. A multi-gene tree showed the three SsV genome types branched within highly supported clades with each of BpV2, OlVs, and MpVs, respectively. Interestingly, transmission electron microscopy also revealed a 190 nm virus-like particle similar the morphology and size of the endosymbiont originally reported in S. scintillans. Overall, we conclude that S. scintillans currently does not harbour an endosymbiotic bacterium, but is associated with giant viruses.
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Affiliation(s)
- Anna Cho
- Department of Botany, University of British Columbia, Vancouver, British Columbia, Canada
| | - Gordon Lax
- Department of Botany, University of British Columbia, Vancouver, British Columbia, Canada
| | - Samuel J. Livingston
- Department of Botany, University of British Columbia, Vancouver, British Columbia, Canada
| | - Yumiko Masukagami
- Okinawa Institute of Science and Technology Graduate University, Okinawa, Japan
| | - Mariia Naumova
- Okinawa Institute of Science and Technology Graduate University, Okinawa, Japan
| | - Olivia Millar
- Okinawa Institute of Science and Technology Graduate University, Okinawa, Japan
| | - Filip Husnik
- Okinawa Institute of Science and Technology Graduate University, Okinawa, Japan
| | - Patrick J. Keeling
- Department of Botany, University of British Columbia, Vancouver, British Columbia, Canada
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3
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Truchon AR, Chase EE, Gann ER, Moniruzzaman M, Creasey BA, Aylward FO, Xiao C, Gobler CJ, Wilhelm SW. Kratosvirus quantuckense: the history and novelty of an algal bloom disrupting virus and a model for giant virus research. Front Microbiol 2023; 14:1284617. [PMID: 38098665 PMCID: PMC10720644 DOI: 10.3389/fmicb.2023.1284617] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2023] [Accepted: 10/30/2023] [Indexed: 12/17/2023] Open
Abstract
Since the discovery of the first "giant virus," particular attention has been paid toward isolating and culturing these large DNA viruses through Acanthamoeba spp. bait systems. While this method has allowed for the discovery of plenty novel viruses in the Nucleocytoviricota, environmental -omics-based analyses have shown that there is a wealth of diversity among this phylum, particularly in marine datasets. The prevalence of these viruses in metatranscriptomes points toward their ecological importance in nutrient turnover in our oceans and as such, in depth study into non-amoebal Nucleocytoviricota should be considered a focal point in viral ecology. In this review, we report on Kratosvirus quantuckense (née Aureococcus anophagefferens Virus), an algae-infecting virus of the Imitervirales. Current systems for study in the Nucleocytoviricota differ significantly from this virus and its relatives, and a litany of trade-offs within physiology, coding potential, and ecology compared to these other viruses reveal the importance of K. quantuckense. Herein, we review the research that has been performed on this virus as well as its potential as a model system for algal-virus interactions.
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Affiliation(s)
- Alexander R Truchon
- Department of Microbiology, University of Tennessee, Knoxville, Knoxville, TN, United States
| | - Emily E Chase
- Department of Microbiology, University of Tennessee, Knoxville, Knoxville, TN, United States
| | - Eric R Gann
- The Henry M. Jackson Foundation for the Advancement of Military Medicine, Inc., Bethesda, MD, United States
- Department of Surgery, Uniformed Services University of the Health Sciences, Bethesda, MD, United States
- Surgical Critical Care Initiative (SC2i), Department of Surgery, Uniformed Services University of the Health Sciences, Bethesda, MD, United States
| | - Mohammad Moniruzzaman
- Department of Marine Biology and Ecology, University of Miami, Miami, FL, United States
| | - Brooke A Creasey
- Department of Microbiology, University of Tennessee, Knoxville, Knoxville, TN, United States
| | - Frank O Aylward
- Department of Biological Sciences, Virginia Tech, Blacksburg, VA, United States
| | - Chuan Xiao
- Department of Chemistry and Biochemistry, The University of Texas at El Paso, El Paso, TX, United States
| | | | - Steven W Wilhelm
- Department of Microbiology, University of Tennessee, Knoxville, Knoxville, TN, United States
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4
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Ge F, Guo R, Liang Y, Chen Y, Shao H, Sung YY, Mok WJ, Wong LL, McMinn A, Wang M. Characterization and genomic analysis of Stutzerimonas stutzeri phage vB_PstS_ZQG1, representing a novel viral genus. Virus Res 2023; 336:199226. [PMID: 37739268 PMCID: PMC10520572 DOI: 10.1016/j.virusres.2023.199226] [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: 06/12/2023] [Revised: 09/11/2023] [Accepted: 09/19/2023] [Indexed: 09/24/2023]
Abstract
Stutzerimonas stutzeri is an opportunistic pathogenic bacterium belonging to the Gammaproteobacteria, exhibiting wide distribution in the environment and playing significant ecological roles such as nitrogen fixation or pollutant degradation. Despite its ecological importance, only two S. stutzeri phages have been isolated to date. Here, a novel S. stutzeri phage, vB_PstS_ZQG1, was isolated from the surface seawater of Qingdao, China. Transmission electron microscopy analysis indicates that vB_PstS_ZQG1 has a morphology characterized by a long non-contractile tail. The genomic sequence of vB_PstS_ZQG1 contains a linear, double-strand 61,790-bp with the G+C content of 53.24% and encodes 90 putative open reading frames. Two auxiliary metabolic genes encoding TolA protein and nucleotide pyrophosphohydrolase were identified, which are likely involved in host adaptation and phage reproduction. Phylogenetic and comparative genomic analyses demonstrated that vB_PstS_ZQG1 exhibits low similarity with previously isolated phages or uncultured viruses (average nucleotide identity values range from 21.7 to 29.4), suggesting that it represents a novel viral genus by itself, here named as Fuevirus. Biogeographic analysis showed that vB_PstS_ZQG1 was only detected in epipelagic and mesopelagic zone with low abundance. In summary, our findings of the phage vB_PstS_ZQG1 will provide helpful insights for further research on the interactions between S. stutzeri phages and their hosts, and contribute to discovering unknown viral sequences in the metagenomic database.
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Affiliation(s)
- Fuyue Ge
- College of Marine Life Sciences, Institute of Evolution and Marine Biodiversity, MoE Laboratory of Evolution and Marine Biodiversity, Frontiers Science Center for Deep Ocean Multispheres and Earth System, Center for Ocean Carbon Neutrality, Ocean University of China, Qingdao, China
| | - Ruizhe Guo
- College of Marine Life Sciences, Institute of Evolution and Marine Biodiversity, MoE Laboratory of Evolution and Marine Biodiversity, Frontiers Science Center for Deep Ocean Multispheres and Earth System, Center for Ocean Carbon Neutrality, Ocean University of China, Qingdao, China
| | - Yantao Liang
- College of Marine Life Sciences, Institute of Evolution and Marine Biodiversity, MoE Laboratory of Evolution and Marine Biodiversity, Frontiers Science Center for Deep Ocean Multispheres and Earth System, Center for Ocean Carbon Neutrality, Ocean University of China, Qingdao, China; UMT-OUC Joint Centre for Marine Studies, Qingdao, China.
| | - Ying Chen
- College of Marine Life Sciences, Institute of Evolution and Marine Biodiversity, MoE Laboratory of Evolution and Marine Biodiversity, Frontiers Science Center for Deep Ocean Multispheres and Earth System, Center for Ocean Carbon Neutrality, Ocean University of China, Qingdao, China
| | - Hongbing Shao
- College of Marine Life Sciences, Institute of Evolution and Marine Biodiversity, MoE Laboratory of Evolution and Marine Biodiversity, Frontiers Science Center for Deep Ocean Multispheres and Earth System, Center for Ocean Carbon Neutrality, Ocean University of China, Qingdao, China; UMT-OUC Joint Centre for Marine Studies, Qingdao, China
| | - Yeong Yik Sung
- UMT-OUC Joint Centre for Marine Studies, Qingdao, China; Institute of Marine Biotechnology, Universiti Malaysia Terengganu, Kuala Terengganu, Malaysia
| | - Wen Jye Mok
- UMT-OUC Joint Centre for Marine Studies, Qingdao, China; Institute of Marine Biotechnology, Universiti Malaysia Terengganu, Kuala Terengganu, Malaysia
| | - Li Lian Wong
- UMT-OUC Joint Centre for Marine Studies, Qingdao, China; Institute of Marine Biotechnology, Universiti Malaysia Terengganu, Kuala Terengganu, Malaysia
| | - Andrew McMinn
- College of Marine Life Sciences, Institute of Evolution and Marine Biodiversity, MoE Laboratory of Evolution and Marine Biodiversity, Frontiers Science Center for Deep Ocean Multispheres and Earth System, Center for Ocean Carbon Neutrality, Ocean University of China, Qingdao, China; Institute for Marine and Antarctic Studies, University of Tasmania, Hobart, TAS, Australia
| | - Min Wang
- College of Marine Life Sciences, Institute of Evolution and Marine Biodiversity, MoE Laboratory of Evolution and Marine Biodiversity, Frontiers Science Center for Deep Ocean Multispheres and Earth System, Center for Ocean Carbon Neutrality, Ocean University of China, Qingdao, China; UMT-OUC Joint Centre for Marine Studies, Qingdao, China; Haide College, Ocean University of China, Qingdao, China; The Affiliated Hospital of Qingdao University, Qingdao, China.
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5
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Moniruzzaman M, Erazo Garcia MP, Farzad R, Ha AD, Jivaji A, Karki S, Sheyn U, Stanton J, Minch B, Stephens D, Hancks DC, Rodrigues RAL, Abrahao JS, Vardi A, Aylward FO. Virologs, viral mimicry, and virocell metabolism: the expanding scale of cellular functions encoded in the complex genomes of giant viruses. FEMS Microbiol Rev 2023; 47:fuad053. [PMID: 37740576 PMCID: PMC10583209 DOI: 10.1093/femsre/fuad053] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2023] [Revised: 08/29/2023] [Accepted: 09/21/2023] [Indexed: 09/24/2023] Open
Abstract
The phylum Nucleocytoviricota includes the largest and most complex viruses known. These "giant viruses" have a long evolutionary history that dates back to the early diversification of eukaryotes, and over time they have evolved elaborate strategies for manipulating the physiology of their hosts during infection. One of the most captivating of these mechanisms involves the use of genes acquired from the host-referred to here as viral homologs or "virologs"-as a means of promoting viral propagation. The best-known examples of these are involved in mimicry, in which viral machinery "imitates" immunomodulatory elements in the vertebrate defense system. But recent findings have highlighted a vast and rapidly expanding array of other virologs that include many genes not typically found in viruses, such as those involved in translation, central carbon metabolism, cytoskeletal structure, nutrient transport, vesicular trafficking, and light harvesting. Unraveling the roles of virologs during infection as well as the evolutionary pathways through which complex functional repertoires are acquired by viruses are important frontiers at the forefront of giant virus research.
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Affiliation(s)
- Mohammad Moniruzzaman
- Rosenstiel School of Marine Atmospheric, and Earth Science, University of Miami, Coral Gables, FL 33149, United States
| | - Maria Paula Erazo Garcia
- Department of Biological Sciences, Virginia Tech, 926 West Campus Drive, Blacksburg, VA 24061, United States
| | - Roxanna Farzad
- Department of Biological Sciences, Virginia Tech, 926 West Campus Drive, Blacksburg, VA 24061, United States
| | - Anh D Ha
- Department of Biological Sciences, Virginia Tech, 926 West Campus Drive, Blacksburg, VA 24061, United States
| | - Abdeali Jivaji
- Department of Biological Sciences, Virginia Tech, 926 West Campus Drive, Blacksburg, VA 24061, United States
| | - Sangita Karki
- Department of Biological Sciences, Virginia Tech, 926 West Campus Drive, Blacksburg, VA 24061, United States
| | - Uri Sheyn
- Department of Biological Sciences, Virginia Tech, 926 West Campus Drive, Blacksburg, VA 24061, United States
| | - Joshua Stanton
- Department of Biological Sciences, Virginia Tech, 926 West Campus Drive, Blacksburg, VA 24061, United States
| | - Benjamin Minch
- Rosenstiel School of Marine Atmospheric, and Earth Science, University of Miami, Coral Gables, FL 33149, United States
| | - Danae Stephens
- Rosenstiel School of Marine Atmospheric, and Earth Science, University of Miami, Coral Gables, FL 33149, United States
| | - Dustin C Hancks
- Department of Immunology, University of Texas Southwestern Medical Center, 6000 Harry Hines Blvd, Dallas, TX, United States
| | - Rodrigo A L Rodrigues
- Laboratório de Vírus, Departamento de Microbiologia, Universidade Federal de Minas Gerais, Belo Horizonte 31270-901, MG, Brazil
| | - Jonatas S Abrahao
- Laboratório de Vírus, Departamento de Microbiologia, Universidade Federal de Minas Gerais, Belo Horizonte 31270-901, MG, Brazil
| | - Assaf Vardi
- Department of Plant and Environmental Sciences, Weizmann Institute of Science, 7610001 Rehovot, Israel
| | - Frank O Aylward
- Department of Biological Sciences, Virginia Tech, 926 West Campus Drive, Blacksburg, VA 24061, United States
- Center for Emerging, Zoonotic, and Arthropod-Borne Infectious Disease, Virginia Tech, Blacksburg, VA 24061, United States
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6
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Wu Z, Chu T, Sheng Y, Yu Y, Wang Y. Diversity, Relationship, and Distribution of Virophages and Large Algal Viruses in Global Ocean Viromes. Viruses 2023; 15:1582. [PMID: 37515268 PMCID: PMC10385804 DOI: 10.3390/v15071582] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2023] [Revised: 07/10/2023] [Accepted: 07/12/2023] [Indexed: 07/30/2023] Open
Abstract
Virophages are a group of small double-stranded DNA viruses that replicate and proliferate with the help of the viral factory of large host viruses. They are widely distributed in aquatic environments but are more abundant in freshwater ecosystems. Here, we mined the Global Ocean Viromes 2.0 (GOV 2.0) dataset for the diversity, distribution, and association of virophages and their potential host large viruses in marine environments. We identified 94 virophage sequences (>5 kbp in length), of which eight were complete genomes. The MCP phylogenetic tree showed that the GOV virophages were widely distributed on the global virophage tree but relatively clustered on three major branches. The gene-sharing network divided GOV virophages into 21 outliers, 2 overlaps, and 14 viral clusters, of which 4 consisted of only the GOV virophages. We also identified 45 large virus sequences, 8 of which were >100 kbp in length and possibly involved in cell-virus-virophage (C-V-v) trisome relationships. The potential eukaryotic hosts of these eight large viruses and the eight virophages with their complete genomes identified are likely to be algae, based on comparative genomic analysis. Both homologous gene and codon usage analyses support a possible interaction between a virophage (GOVv18) and a large algal virus (GOVLV1). These results indicate that diverse and novel virophages and large viruses are widespread in global marine environments, suggesting their important roles and the presence of complicated unknown C-V-v relationships in marine ecosystems.
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Affiliation(s)
- Zhenqi Wu
- College of Food Science and Technology, Shanghai Ocean University, Shanghai 201304, China
| | - Ting Chu
- College of Food Science and Technology, Shanghai Ocean University, Shanghai 201304, China
| | - Yijian Sheng
- College of Food Science and Technology, Shanghai Ocean University, Shanghai 201304, China
| | - Yongxin Yu
- College of Food Science and Technology, Shanghai Ocean University, Shanghai 201304, China
- Laboratory of Quality and Safety Risk Assessment for Aquatic Products on Storage and Preservation (Shanghai), Ministry of Agriculture and Rural Affairs, Shanghai 201304, China
| | - Yongjie Wang
- College of Food Science and Technology, Shanghai Ocean University, Shanghai 201304, China
- Laboratory of Quality and Safety Risk Assessment for Aquatic Products on Storage and Preservation (Shanghai), Ministry of Agriculture and Rural Affairs, Shanghai 201304, China
- Laboratory for Marine Biology and Biotechnology, Qingdao National Laboratory for Marine Science and Technology, Qingdao 266000, China
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7
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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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8
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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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9
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Farzad R, Ha AD, Aylward FO. Diversity and genomics of giant viruses in the North Pacific Subtropical Gyre. Front Microbiol 2022; 13:1021923. [PMID: 36504832 PMCID: PMC9732441 DOI: 10.3389/fmicb.2022.1021923] [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: 08/17/2022] [Accepted: 10/25/2022] [Indexed: 11/27/2022] Open
Abstract
Large double-stranded DNA viruses of the phylum Nucleocytoviricota, often referred to as "giant viruses," are ubiquitous members of marine ecosystems that are important agents of mortality for eukaryotic plankton. Although giant viruses are known to be prevalent in marine systems, their activities in oligotrophic ocean waters remain unclear. Oligotrophic gyres constitute the majority of the ocean and assessing viral activities in these regions is therefore critical for understanding overall marine microbial processes. In this study, we generated 11 metagenome-assembled genomes (MAGs) of giant viruses from samples previously collected from Station ALOHA in the North Pacific Subtropical Gyre. Phylogenetic analyses revealed that they belong to the orders Imitervirales (n = 6), Algavirales (n = 4), and Pimascovirales (n = 1). Genome sizes ranged from ~119-574 kbp, and several of the genomes encoded predicted TCA cycle components, cytoskeletal proteins, collagen, rhodopsins, and proteins potentially involved in other cellular processes. Comparison with other marine metagenomes revealed that several have broad distribution across ocean basins and represent abundant viral constituents of pelagic surface waters. Our work sheds light on the diversity of giant viruses present in oligotrophic ocean waters across the globe.
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Affiliation(s)
- Roxanna Farzad
- Department of Biological Sciences, Virginia Tech, Blacksburg, VA, United States
| | - Anh D. Ha
- Department of Biological Sciences, Virginia Tech, Blacksburg, VA, United States
| | - Frank O. Aylward
- Department of Biological Sciences, Virginia Tech, Blacksburg, VA, United States,Center for Emerging, Zoonotic, and Arthropod-Borne Infectious Disease, Virginia Tech, Blacksburg, VA, United States,*Correspondence: Frank O. Aylward,
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10
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Speciale I, Notaro A, Abergel C, Lanzetta R, Lowary TL, Molinaro A, Tonetti M, Van Etten JL, De Castro C. The Astounding World of Glycans from Giant Viruses. Chem Rev 2022; 122:15717-15766. [PMID: 35820164 PMCID: PMC9614988 DOI: 10.1021/acs.chemrev.2c00118] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
![]()
Viruses are a heterogeneous ensemble of entities, all
sharing the
need for a suitable host to replicate. They are extremely diverse,
varying in morphology, size, nature, and complexity of their genomic
content. Typically, viruses use host-encoded glycosyltransferases
and glycosidases to add and remove sugar residues from their glycoproteins.
Thus, the structure of the glycans on the viral proteins have, to
date, typically been considered to mimick those of the host. However,
the more recently discovered large and giant viruses differ from this
paradigm. At least some of these viruses code for an (almost) autonomous
glycosylation pathway. These viral genes include those that encode
the production of activated sugars, glycosyltransferases, and other
enzymes able to manipulate sugars at various levels. This review focuses
on large and giant viruses that produce carbohydrate-processing enzymes.
A brief description of those harboring these features at the genomic
level will be discussed, followed by the achievements reached with
regard to the elucidation of the glycan structures, the activity of
the proteins able to manipulate sugars, and the organic synthesis
of some of these virus-encoded glycans. During this progression, we
will also comment on many of the challenging questions on this subject
that remain to be addressed.
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Affiliation(s)
- Immacolata Speciale
- Department of Agricultural Sciences, University of Napoli, Via Università 100, 80055 Portici, Italy
| | - Anna Notaro
- Department of Agricultural Sciences, University of Napoli, Via Università 100, 80055 Portici, Italy.,Centre National de la Recherche Scientifique, Information Génomique & Structurale, Aix-Marseille University, Unité Mixte de Recherche 7256, IMM, IM2B, 13288 Marseille, Cedex 9, France
| | - Chantal Abergel
- Centre National de la Recherche Scientifique, Information Génomique & Structurale, Aix-Marseille University, Unité Mixte de Recherche 7256, IMM, IM2B, 13288 Marseille, Cedex 9, France
| | - Rosa Lanzetta
- Department of Chemical Sciences, University of Napoli, Via Cintia 4, 80126 Napoli, Italy
| | - Todd L Lowary
- Institute of Biological Chemistry, Academia Sinica, Academia Road, Section 2, Nangang 11529, Taipei, Taiwan
| | - Antonio Molinaro
- Department of Chemical Sciences, University of Napoli, Via Cintia 4, 80126 Napoli, Italy
| | - Michela Tonetti
- Department of Experimental Medicine and Center of Excellence for Biomedical Research, University of Genova, 16132 Genova, Italy
| | - James L Van Etten
- Nebraska Center for Virology, University of Nebraska, Lincoln, Nebraska 68583-0900, United States.,Department of Plant Pathology, University of Nebraska, Lincoln, Nebraska 68583-0722, United States
| | - Cristina De Castro
- Department of Agricultural Sciences, University of Napoli, Via Università 100, 80055 Portici, Italy
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11
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Park SH, Kyndt JA, Brown JK. Comparison of Auxenochlorella protothecoides and Chlorella spp. Chloroplast Genomes: Evidence for Endosymbiosis and Horizontal Virus-like Gene Transfer. Life (Basel) 2022; 12:life12030458. [PMID: 35330209 PMCID: PMC8955559 DOI: 10.3390/life12030458] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2022] [Revised: 03/15/2022] [Accepted: 03/16/2022] [Indexed: 12/02/2022] Open
Abstract
Resequencing of the chloroplast genome (cpDNA) of Auxenochlorella protothecoides UTEX 25 was completed (GenBank Accession no. KC631634.1), revealing a genome size of 84,576 base pairs and 30.8% GC content, consistent with features reported for the previously sequenced A. protothecoides 0710, (GenBank Accession no. KC843975). The A. protothecoides UTEX 25 cpDNA encoded 78 predicted open reading frames, 32 tRNAs, and 4 rRNAs, making it smaller and more compact than the cpDNA genome of C. variabilis (124,579 bp) and C. vulgaris (150,613 bp). By comparison, the compact genome size of A. protothecoides was attributable primarily to a lower intergenic sequence content. The cpDNA coding regions of all known Chlorella species were found to be organized in conserved colinear blocks, with some rearrangements. The Auxenochlorella and Chlorella species genome structure and composition were similar, and of particular interest were genes influencing photosynthetic efficiency, i.e., chlorophyll synthesis and photosystem subunit I and II genes, consistent with other biofuel species of interest. Phylogenetic analysis revealed that Prototheca cutis is the closest known A. protothecoides relative, followed by members of the genus Chlorella. The cpDNA of A. protothecoides encodes 37 genes that are highly homologous to representative cyanobacteria species, including rrn16, rrn23, and psbA, corroborating a well-recognized symbiosis. Several putative coding regions were identified that shared high nucleotide sequence identity with virus-like sequences, suggestive of horizontal gene transfer. Despite these predictions, no corresponding transcripts were obtained by RT-PCR amplification, indicating they are unlikely to be expressed in the extant lineage.
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Affiliation(s)
- Sang-Hyuck Park
- School of Plant Sciences, The University of Arizona, Tucson, AZ 85721, USA; (S.-H.P.); (J.K.B.)
- Institute of Cannabis Research, Colorado State University-Pueblo, Pueblo, CO 81001, USA
| | - John A. Kyndt
- College of Science and Technology, Bellevue University, Bellevue, NE 68005, USA
- Correspondence:
| | - Judith K. Brown
- School of Plant Sciences, The University of Arizona, Tucson, AZ 85721, USA; (S.-H.P.); (J.K.B.)
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12
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Diversity and Evolution of Mamiellophyceae: Early-Diverging Phytoplanktonic Green Algae Containing Many Cosmopolitan Species. JOURNAL OF MARINE SCIENCE AND ENGINEERING 2022. [DOI: 10.3390/jmse10020240] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
The genomic revolution has bridged a gap in our knowledge about the diversity, biology and evolution of unicellular photosynthetic eukaryotes, which bear very few discriminating morphological features among species from the same genus. The high-quality genome resources available in the class Mamiellophyceae (Chlorophyta) have been paramount to estimate species diversity and screen available metagenomic data to assess the biogeography and ecological niches of different species on a global scale. Here we review the current knowledge about the diversity, ecology and evolution of the Mamiellophyceae and the large double-stranded DNA prasinoviruses infecting them, brought by the combination of genomic and metagenomic analyses, including 26 metabarcoding environmental studies, as well as the pan-oceanic GOS and the Tara Oceans expeditions.
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13
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Viruses infecting a warm water picoeukaryote shed light on spatial co-occurrence dynamics of marine viruses and their hosts. THE ISME JOURNAL 2021; 15:3129-3147. [PMID: 33972727 PMCID: PMC8528832 DOI: 10.1038/s41396-021-00989-9] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/27/2020] [Revised: 03/08/2021] [Accepted: 04/14/2021] [Indexed: 02/03/2023]
Abstract
The marine picoeukaryote Bathycoccus prasinos has been considered a cosmopolitan alga, although recent studies indicate two ecotypes exist, Clade BI (B. prasinos) and Clade BII. Viruses that infect Bathycoccus Clade BI are known (BpVs), but not that infect BII. We isolated three dsDNA prasinoviruses from the Sargasso Sea against Clade BII isolate RCC716. The BII-Vs do not infect BI, and two (BII-V2 and BII-V3) have larger genomes (~210 kb) than BI-Viruses and BII-V1. BII-Vs share ~90% of their proteins, and between 65% to 83% of their proteins with sequenced BpVs. Phylogenomic reconstructions and PolB analyses establish close-relatedness of BII-V2 and BII-V3, yet BII-V2 has 10-fold higher infectivity and induces greater mortality on host isolate RCC716. BII-V1 is more distant, has a shorter latent period, and infects both available BII isolates, RCC716 and RCC715, while BII-V2 and BII-V3 do not exhibit productive infection of the latter in our experiments. Global metagenome analyses show Clade BI and BII algal relative abundances correlate positively with their respective viruses. The distributions delineate BI/BpVs as occupying lower temperature mesotrophic and coastal systems, whereas BII/BII-Vs occupy warmer temperature, higher salinity ecosystems. Accordingly, with molecular diagnostic support, we name Clade BII Bathycoccus calidus sp. nov. and propose that molecular diversity within this new species likely connects to the differentiated host-virus dynamics observed in our time course experiments. Overall, the tightly linked biogeography of Bathycoccus host and virus clades observed herein supports species-level host specificity, with strain-level variations in infection parameters.
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14
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Aylward FO, Moniruzzaman M, Ha AD, Koonin EV. A phylogenomic framework for charting the diversity and evolution of giant viruses. PLoS Biol 2021; 19:e3001430. [PMID: 34705818 PMCID: PMC8575486 DOI: 10.1371/journal.pbio.3001430] [Citation(s) in RCA: 41] [Impact Index Per Article: 13.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2021] [Revised: 11/08/2021] [Accepted: 09/29/2021] [Indexed: 11/22/2022] Open
Abstract
Large DNA viruses of the phylum Nucleocytoviricota have recently emerged as important members of ecosystems around the globe that challenge traditional views of viral complexity. Numerous members of this phylum that cannot be classified within established families have recently been reported, and there is presently a strong need for a robust phylogenomic and taxonomic framework for these viruses. Here, we report a comprehensive phylogenomic analysis of the Nucleocytoviricota, present a set of giant virus orthologous groups (GVOGs) together with a benchmarked reference phylogeny, and delineate a hierarchical taxonomy within this phylum. We show that the majority of Nucleocytoviricota diversity can be partitioned into 6 orders, 32 families, and 344 genera, substantially expanding the number of currently recognized taxonomic ranks for these viruses. We integrate our results within a taxonomy that has been adopted for all viruses to establish a unifying framework for the study of Nucleocytoviricota diversity, evolution, and environmental distribution. Giant viruses have transformed our understanding of viral complexity, but we lack a framework for examining their diversity in the biosphere. This study presents a phylogenomic resource for charting the diversity, ecology, and evolution of giant viruses.
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Affiliation(s)
- Frank O. Aylward
- Department of Biological Sciences, Virginia Tech, Blacksburg, Virginia, United States of America
- Center for Emerging, Zoonotic, and Arthropod-borne Pathogens, Virginia Tech, Blacksburg, Virginia, United States of America
- * E-mail:
| | - Mohammad Moniruzzaman
- Department of Biological Sciences, Virginia Tech, Blacksburg, Virginia, United States of America
| | - Anh D. Ha
- Department of Biological Sciences, Virginia Tech, Blacksburg, Virginia, United States of America
| | - Eugene V. Koonin
- National Center for Biotechnology Information, National Library of Medicine, National Institutes of Health, Bethesda, Maryland, United States of America
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15
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Viral Characteristics of the Warm Atlantic and Cold Arctic Water Masses in the Nordic Seas. Appl Environ Microbiol 2021; 87:e0116021. [PMID: 34469192 DOI: 10.1128/aem.01160-21] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
Nordic Seas are the subarctic seas connecting the Arctic Ocean and North Atlantic Ocean with complex water masses, experiencing an abrupt climate change. Though knowledge of the marine virosphere has expanded rapidly, the diversity of viruses and their relationships with host cells and water masses in the Nordic Seas remain to be fully revealed. Here, we establish the Nordic Sea DNA virome (NSV) data set of 55,315 viral contigs including 1,478 unique viral populations from seven stations influenced by both the warm Atlantic and cold Arctic water masses. Caudovirales dominated in the seven NSVs, especially in the warm Atlantic waters. The major giant nucleocytoplasmic large DNA viruses (NCLDVs) contributed a significant proportion of the classified viral contigs in the NSVs (32.2%), especially in the cold Arctic waters (44.9%). The distribution patterns of Caudovirales and NCLDVs were a reflection of the community structure of their hosts in the corresponding water masses and currents. Latitude, pH, and flow speed were found to be key factors influencing the microbial communities and coinfluencing the variation of viral communities. Network analysis illustrated the tight coupling between the variation of viral communities and microbial communities in the Nordic Seas. This study suggests a probable linkage between viromes, host cells, and surface water masses from both the cool Arctic and warm Atlantic Oceans. IMPORTANCE This is a systematic study of Nordic Sea viromes using metagenomic analysis. The viral diversity, community structure, and their relationships with host cells and the complex water masses from both the cool Arctic and the warm Atlantic oceans were illustrated. The NCLDVs and Caudovirales are proposed as the viral characteristics of the cold Arctic and warm Atlantic waters, respectively. This study provides an important background for the viromes in the subarctic seas connecting the Arctic Ocean and North Atlantic Ocean and sheds light on their responses to abrupt climate change in the future.
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16
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Ha AD, Moniruzzaman M, Aylward FO. High Transcriptional Activity and Diverse Functional Repertoires of Hundreds of Giant Viruses in a Coastal Marine System. mSystems 2021; 6:e0029321. [PMID: 34254826 PMCID: PMC8407384 DOI: 10.1128/msystems.00293-21] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2021] [Accepted: 05/26/2021] [Indexed: 12/14/2022] Open
Abstract
Viruses belonging to the Nucleocytoviricota phylum are globally distributed and include members with notably large genomes and complex functional repertoires. Recent studies have shown that these viruses are particularly diverse and abundant in marine systems, but the magnitude of actively replicating Nucleocytoviricota present in ocean habitats remains unclear. In this study, we compiled a curated database of 2,431 Nucleocytoviricota genomes and used it to examine the gene expression of these viruses in a 2.5-day metatranscriptomic time-series from surface waters of the California Current. We identified 145 viral genomes with high levels of gene expression, including 90 Imitervirales and 49 Algavirales viruses. In addition to recovering high expression of core genes involved in information processing that are commonly expressed during viral infection, we also identified transcripts of diverse viral metabolic genes from pathways such as glycolysis, the TCA cycle, and the pentose phosphate pathway, suggesting that virus-mediated reprogramming of central carbon metabolism is common in oceanic surface waters. Surprisingly, we also identified viral transcripts with homology to actin, myosin, and kinesin domains, suggesting that viruses may use these gene products to manipulate host cytoskeletal dynamics during infection. We performed phylogenetic analysis on the virus-encoded myosin and kinesin proteins, which demonstrated that most belong to deep-branching viral clades, but that others appear to have been acquired from eukaryotes more recently. Our results highlight a remarkable diversity of active Nucleocytoviricota in a coastal marine system and underscore the complex functional repertoires expressed by these viruses during infection. IMPORTANCE The discovery of giant viruses has transformed our understanding of viral complexity. Although viruses have traditionally been viewed as filterable infectious agents that lack metabolism, giant viruses can reach sizes rivalling cellular lineages and possess genomes encoding central metabolic processes. Recent studies have shown that giant viruses are widespread in aquatic systems, but the activity of these viruses and the extent to which they reprogram host physiology in situ remains unclear. Here, we show that numerous giant viruses consistently express central metabolic enzymes in a coastal marine system, including components of glycolysis, the TCA cycle, and other pathways involved in nutrient homeostasis. Moreover, we found expression of several viral-encoded actin, myosin, and kinesin genes, indicating viral manipulation of the host cytoskeleton during infection. Our study reveals a high activity of giant viruses in a coastal marine system and indicates they are a diverse and underappreciated component of microbial diversity in the ocean.
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Affiliation(s)
- Anh D. Ha
- Department of Biological Sciences, Virginia Tech, Blacksburg, Virginia, USA
| | | | - Frank O. Aylward
- Department of Biological Sciences, Virginia Tech, Blacksburg, Virginia, USA
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17
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Karki S, Moniruzzaman M, Aylward FO. Comparative Genomics and Environmental Distribution of Large dsDNA Viruses in the Family Asfarviridae. Front Microbiol 2021; 12:657471. [PMID: 33790885 PMCID: PMC8005611 DOI: 10.3389/fmicb.2021.657471] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2021] [Accepted: 02/22/2021] [Indexed: 12/14/2022] Open
Abstract
The family Asfarviridae is a group of nucleo-cytoplasmic large DNA viruses (NCLDVs) of which African swine fever virus (ASFV) is well-characterized. Recently the discovery of several Asfarviridae members other than ASFV has suggested that this family represents a diverse and cosmopolitan group of viruses, but the genomics and distribution of this family have not been studied in detail. To this end we analyzed five complete genomes and 35 metagenome-assembled genomes (MAGs) of viruses from this family to shed light on their evolutionary relationships and environmental distribution. The Asfarvirus MAGs derive from diverse marine, freshwater, and terrestrial habitats, underscoring the broad environmental distribution of this family. We present phylogenetic analyses using conserved marker genes and whole-genome comparison of pairwise average amino acid identity (AAI) values, revealing a high level of genomic divergence across disparate Asfarviruses. Further, we found that Asfarviridae genomes encode genes with diverse predicted metabolic roles and detectable sequence homology to proteins in bacteria, archaea, and eukaryotes, highlighting the genomic chimerism that is a salient feature of NCLDV. Our read mapping from Tara oceans metagenomic data also revealed that three Asfarviridae MAGs were present in multiple marine samples, indicating that they are widespread in the ocean. In one of these MAGs we identified four marker genes with > 95% AAI to genes sequenced from a virus that infects the dinoflagellate Heterocapsa circularisquama (HcDNAV). This suggests a potential host for this MAG, which would thereby represent a reference genome of a dinoflagellate-infecting giant virus. Together, these results show that Asfarviridae are ubiquitous, comprise similar sequence divergence as other NCLDV families, and include several members that are widespread in the ocean and potentially infect ecologically important protists.
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Affiliation(s)
- Sangita Karki
- Department of Biological Sciences, Virginia Tech, Blacksburg, VA, United States
| | | | - Frank O Aylward
- Department of Biological Sciences, Virginia Tech, Blacksburg, VA, United States
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18
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Liem M, Regensburg-Tuïnk T, Henkel C, Jansen H, Spaink H. Microbial diversity characterization of seawater in a pilot study using Oxford Nanopore Technologies long-read sequencing. BMC Res Notes 2021; 14:42. [PMID: 33531031 PMCID: PMC7852107 DOI: 10.1186/s13104-021-05457-3] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2020] [Accepted: 01/20/2021] [Indexed: 11/10/2022] Open
Abstract
OBJECTIVE Currently the majority of non-culturable microbes in sea water are yet to be discovered, Nanopore offers a solution to overcome the challenging tasks to identify the genomes and complex composition of oceanic microbiomes. In this study we evaluate the utility of Oxford Nanopore Technologies (ONT) sequencing to characterize microbial diversity in seawater from multiple locations. We compared the microbial species diversity of retrieved environmental samples from two different locations and time points. RESULTS With only three ONT flow cells we were able to identify thousands of organisms, including bacteriophages, from which a large part at species level. It was possible to assemble genomes from environmental samples with Flye. In several cases this resulted in > 1 Mbp contigs and in the particular case of a Thioglobus singularis species it even produced a near complete genome. k-mer analysis reveals that a large part of the data represents species of which close relatives have not yet been deposited to the database. These results show that our approach is suitable for scalable genomic investigations such as monitoring oceanic biodiversity and provides a new platform for education in biodiversity.
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Affiliation(s)
- M Liem
- Institute Biology, Leiden University, Sylviusweg 72, 2333 BE, Leiden, The Netherlands.
| | - T Regensburg-Tuïnk
- Institute Biology, Leiden University, Sylviusweg 72, 2333 BE, Leiden, The Netherlands
| | - C Henkel
- Norwegian University of Life Sciences (NMBU), Ås, Norway
| | - H Jansen
- Future Genomics Technologies, Leiden, The Netherlands
| | - H Spaink
- Institute Biology, Leiden University, Sylviusweg 72, 2333 BE, Leiden, The Netherlands
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19
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Aylward FO, Moniruzzaman M. ViralRecall-A Flexible Command-Line Tool for the Detection of Giant Virus Signatures in 'Omic Data. Viruses 2021; 13:v13020150. [PMID: 33498458 PMCID: PMC7909515 DOI: 10.3390/v13020150] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2020] [Revised: 01/07/2021] [Accepted: 01/18/2021] [Indexed: 01/06/2023] Open
Abstract
Giant viruses are widespread in the biosphere and play important roles in biogeochemical cycling and host genome evolution. Also known as nucleo-cytoplasmic large DNA viruses (NCLDVs), these eukaryotic viruses harbor the largest and most complex viral genomes known. Studies have shown that NCLDVs are frequently abundant in metagenomic datasets, and that sequences derived from these viruses can also be found endogenized in diverse eukaryotic genomes. The accurate detection of sequences derived from NCLDVs is therefore of great importance, but this task is challenging owing to both the high level of sequence divergence between NCLDV families and the extraordinarily high diversity of genes encoded in their genomes, including some encoding for metabolic or translation-related functions that are typically found only in cellular lineages. Here, we present ViralRecall, a bioinformatic tool for the identification of NCLDV signatures in ‘omic data. This tool leverages a library of giant virus orthologous groups (GVOGs) to identify sequences that bear signatures of NCLDVs. We demonstrate that this tool can effectively identify NCLDV sequences with high sensitivity and specificity. Moreover, we show that it can be useful both for removing contaminating sequences in metagenome-assembled viral genomes as well as the identification of eukaryotic genomic loci that derived from NCLDV. ViralRecall is written in Python 3.5 and is freely available on GitHub: https://github.com/faylward/viralrecall.
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20
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Sun TW, Yang CL, Kao TT, Wang TH, Lai MW, Ku C. Host Range and Coding Potential of Eukaryotic Giant Viruses. Viruses 2020; 12:E1337. [PMID: 33233432 PMCID: PMC7700475 DOI: 10.3390/v12111337] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2020] [Revised: 11/19/2020] [Accepted: 11/19/2020] [Indexed: 12/11/2022] Open
Abstract
Giant viruses are a group of eukaryotic double-stranded DNA viruses with large virion and genome size that challenged the traditional view of virus. Newly isolated strains and sequenced genomes in the last two decades have substantially advanced our knowledge of their host diversity, gene functions, and evolutionary history. Giant viruses are now known to infect hosts from all major supergroups in the eukaryotic tree of life, which predominantly comprises microbial organisms. The seven well-recognized viral clades (taxonomic families) have drastically different host range. Mimiviridae and Phycodnaviridae, both with notable intrafamilial genome variation and high abundance in environmental samples, have members that infect the most diverse eukaryotic lineages. Laboratory experiments and comparative genomics have shed light on the unprecedented functional potential of giant viruses, encoding proteins for genetic information flow, energy metabolism, synthesis of biomolecules, membrane transport, and sensing that allow for sophisticated control of intracellular conditions and cell-environment interactions. Evolutionary genomics can illuminate how current and past hosts shape viral gene repertoires, although it becomes more obscure with divergent sequences and deep phylogenies. Continued works to characterize giant viruses from marine and other environments will further contribute to our understanding of their host range, coding potential, and virus-host coevolution.
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Affiliation(s)
- Tsu-Wang Sun
- Institute of Plant and Microbial Biology, Academia Sinica, Taipei 11529, Taiwan; (T.-W.S.); (C.-L.Y.); (T.-T.K.); (T.-H.W.); (M.-W.L.)
- Genome and Systems Biology Degree Program, National Taiwan University and Academia Sinica, Taipei 10617, Taiwan
| | - Chia-Ling Yang
- Institute of Plant and Microbial Biology, Academia Sinica, Taipei 11529, Taiwan; (T.-W.S.); (C.-L.Y.); (T.-T.K.); (T.-H.W.); (M.-W.L.)
| | - Tzu-Tong Kao
- Institute of Plant and Microbial Biology, Academia Sinica, Taipei 11529, Taiwan; (T.-W.S.); (C.-L.Y.); (T.-T.K.); (T.-H.W.); (M.-W.L.)
| | - Tzu-Haw Wang
- Institute of Plant and Microbial Biology, Academia Sinica, Taipei 11529, Taiwan; (T.-W.S.); (C.-L.Y.); (T.-T.K.); (T.-H.W.); (M.-W.L.)
| | - Ming-Wei Lai
- Institute of Plant and Microbial Biology, Academia Sinica, Taipei 11529, Taiwan; (T.-W.S.); (C.-L.Y.); (T.-T.K.); (T.-H.W.); (M.-W.L.)
| | - Chuan Ku
- Institute of Plant and Microbial Biology, Academia Sinica, Taipei 11529, Taiwan; (T.-W.S.); (C.-L.Y.); (T.-T.K.); (T.-H.W.); (M.-W.L.)
- Genome and Systems Biology Degree Program, National Taiwan University and Academia Sinica, Taipei 10617, Taiwan
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21
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Shrinking of repeating unit length in leucine-rich repeats from double-stranded DNA viruses. Arch Virol 2020; 166:43-64. [PMID: 33052487 DOI: 10.1007/s00705-020-04820-2] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2020] [Accepted: 08/19/2020] [Indexed: 02/07/2023]
Abstract
Leucine-rich repeats (LRRs) are present in over 563,000 proteins from viruses to eukaryotes. LRRs repeat in tandem and have been classified into fifteen classes in which the repeat unit lengths range from 20 to 29 residues. Most LRR proteins are involved in protein-protein or ligand interactions. The amount of genome sequence data from viruses is increasing rapidly, and although viral LRR proteins have been identified, a comprehensive sequence analysis has not yet been done, and their structures, functions, and evolution are still unknown. In the present study, we characterized viral LRRs by sequence analysis and identified over 600 LRR proteins from 89 virus species. Most of these proteins were from double-stranded DNA (dsDNA) viruses, including nucleocytoplasmic large dsDNA viruses (NCLDVs). We found that the repeating unit lengths of 11 types are one to five residues shorter than those of the seven known corresponding LRR classes. The repeating units of six types are 19 residues long and are thus the shortest among all LRRs. In addition, two of the LRR types are unique and have not been observed in bacteria, archae or eukaryotes. Conserved strongly hydrophobic residues such as Leu, Val or Ile in the consensus sequences are replaced by Cys with high frequency. Phylogenetic analysis indicated that horizontal gene transfer of some viral LRR genes had occurred between the virus and its host. We suggest that the shortening might contribute to the survival strategy of viruses. The present findings provide a new perspective on the origin and evolution of LRRs.
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22
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Yau S, Krasovec M, Benites LF, Rombauts S, Groussin M, Vancaester E, Aury JM, Derelle E, Desdevises Y, Escande ML, Grimsley N, Guy J, Moreau H, Sanchez-Brosseau S, van de Peer Y, Vandepoele K, Gourbiere S, Piganeau G. Virus-host coexistence in phytoplankton through the genomic lens. SCIENCE ADVANCES 2020; 6:eaay2587. [PMID: 32270031 PMCID: PMC7112755 DOI: 10.1126/sciadv.aay2587] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/04/2019] [Accepted: 01/09/2020] [Indexed: 05/02/2023]
Abstract
Virus-microbe interactions in the ocean are commonly described by "boom and bust" dynamics, whereby a numerically dominant microorganism is lysed and replaced by a virus-resistant one. Here, we isolated a microalga strain and its infective dsDNA virus whose dynamics are characterized instead by parallel growth of both the microalga and the virus. Experimental evolution of clonal lines revealed that this viral production originates from the lysis of a minority of virus-susceptible cells, which are regenerated from resistant cells. Whole-genome sequencing demonstrated that this resistant-susceptible switch involved a large deletion on one chromosome. Mathematical modeling explained how the switch maintains stable microalga-virus population dynamics consistent with their observed growth pattern. Comparative genomics confirmed an ancient origin of this "accordion" chromosome despite a lack of sequence conservation. Together, our results show how dynamic genomic rearrangements may account for a previously overlooked coexistence mechanism in microalgae-virus interactions.
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Affiliation(s)
- Sheree Yau
- Sorbonne Université, CNRS, UMR 7232 Biologie Intégrative des Organismes Marins (BIOM), Observatoire Océanologique, F-66650 Banyuls-sur-Mer, France
- Department of Marine Biology and Oceanography, Institute of Marine Sciences (ICM), CSIC, Barcelona, Spain
- Corresponding author. (G.P.); (S.Y.)
| | - Marc Krasovec
- Sorbonne Université, CNRS, UMR 7232 Biologie Intégrative des Organismes Marins (BIOM), Observatoire Océanologique, F-66650 Banyuls-sur-Mer, France
| | - L. Felipe Benites
- Sorbonne Université, CNRS, UMR 7232 Biologie Intégrative des Organismes Marins (BIOM), Observatoire Océanologique, F-66650 Banyuls-sur-Mer, France
| | - Stephane Rombauts
- Ghent University, Department of Plant Biotechnology and Bioinformatics, Technologiepark-Zwijnaarde 71, 9052 Ghent, Belgium
- VIB Center for Plant Systems Biology, Technologiepark-Zwijnaarde 71, 9052 Ghent, Belgium
| | - Mathieu Groussin
- Department of Biological Engineering, Massachusetts Institute of Technology, 500 Technology Square NE47-378, Cambridge, MA 02139, USA
| | - Emmelien Vancaester
- Ghent University, Department of Plant Biotechnology and Bioinformatics, Technologiepark-Zwijnaarde 71, 9052 Ghent, Belgium
- VIB Center for Plant Systems Biology, Technologiepark-Zwijnaarde 71, 9052 Ghent, Belgium
| | - Jean-Marc Aury
- Genoscope, Institut de biologie François Jacob, Commissariat à l’Energie Atomique (CEA), Université Paris-Saclay, Evry, France
| | - Evelyne Derelle
- Sorbonne Université, CNRS, UMR 7232 Biologie Intégrative des Organismes Marins (BIOM), Observatoire Océanologique, F-66650 Banyuls-sur-Mer, France
- Univ. Brest, CNRS, IRD, Ifremer, LEMAR, F-29280 Plouzane, France
| | - Yves Desdevises
- Sorbonne Université, CNRS, UMR 7232 Biologie Intégrative des Organismes Marins (BIOM), Observatoire Océanologique, F-66650 Banyuls-sur-Mer, France
| | - Marie-Line Escande
- Sorbonne Université, CNRS, UMR 7232 Biologie Intégrative des Organismes Marins (BIOM), Observatoire Océanologique, F-66650 Banyuls-sur-Mer, France
| | - Nigel Grimsley
- Sorbonne Université, CNRS, UMR 7232 Biologie Intégrative des Organismes Marins (BIOM), Observatoire Océanologique, F-66650 Banyuls-sur-Mer, France
| | - Julie Guy
- Genoscope, Institut de biologie François Jacob, Commissariat à l’Energie Atomique (CEA), Université Paris-Saclay, Evry, France
| | - Hervé Moreau
- Sorbonne Université, CNRS, UMR 7232 Biologie Intégrative des Organismes Marins (BIOM), Observatoire Océanologique, F-66650 Banyuls-sur-Mer, France
| | - Sophie Sanchez-Brosseau
- Sorbonne Université, CNRS, UMR 7232 Biologie Intégrative des Organismes Marins (BIOM), Observatoire Océanologique, F-66650 Banyuls-sur-Mer, France
| | - Yves van de Peer
- Ghent University, Department of Plant Biotechnology and Bioinformatics, Technologiepark-Zwijnaarde 71, 9052 Ghent, Belgium
- VIB Center for Plant Systems Biology, Technologiepark-Zwijnaarde 71, 9052 Ghent, Belgium
- Department of Biochemistry, Genetics and Microbiology, University of Pretoria, Pretoria 0028, South Africa
| | - Klaas Vandepoele
- Ghent University, Department of Plant Biotechnology and Bioinformatics, Technologiepark-Zwijnaarde 71, 9052 Ghent, Belgium
- VIB Center for Plant Systems Biology, Technologiepark-Zwijnaarde 71, 9052 Ghent, Belgium
| | - Sebastien Gourbiere
- Laboratoire Génome et Développement des Plantes, Université de Perpignan Via Domitia, UMR 5096, 52 Avenue Paul Alduy, 66860 Perpignan, France
| | - Gwenael Piganeau
- Sorbonne Université, CNRS, UMR 7232 Biologie Intégrative des Organismes Marins (BIOM), Observatoire Océanologique, F-66650 Banyuls-sur-Mer, France
- Corresponding author. (G.P.); (S.Y.)
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23
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Luo E, Eppley JM, Romano AE, Mende DR, DeLong EF. Double-stranded DNA virioplankton dynamics and reproductive strategies in the oligotrophic open ocean water column. ISME JOURNAL 2020; 14:1304-1315. [PMID: 32060418 PMCID: PMC7174320 DOI: 10.1038/s41396-020-0604-8] [Citation(s) in RCA: 45] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/06/2019] [Revised: 12/17/2019] [Accepted: 01/30/2020] [Indexed: 12/11/2022]
Abstract
Microbial communities are critical to ecosystem dynamics and biogeochemical cycling in the open oceans. Viruses are essential elements of these communities, influencing the productivity, diversity, and evolution of cellular hosts. To further explore the natural history and ecology of open-ocean viruses, we surveyed the spatiotemporal dynamics of double-stranded DNA (dsDNA) viruses in both virioplankton and bacterioplankton size fractions in the North Pacific Subtropical Gyre, one of the largest biomes on the planet. Assembly and clustering of viral genomes revealed a peak in virioplankton diversity at the base of the euphotic zone, where virus populations and host species richness both reached their maxima. Simultaneous characterization of both extracellular and intracellular viruses suggested depth-specific reproductive strategies. In particular, analyses indicated elevated lytic interactions in the mixed layer, more temporally variable temperate phage interactions at the base of the euphotic zone, and increased lysogeny in the mesopelagic ocean. Furthermore, the depth variability of auxiliary metabolic genes suggested habitat-specific strategies for viral influence on light-energy, nitrogen, and phosphorus acquisition during host infection. Most virus populations were temporally persistent over several years in this environment at the 95% nucleic acid identity level. In total, our analyses revealed variable distributional patterns and diverse reproductive and metabolic strategies of virus populations in the open-ocean water column.
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Affiliation(s)
- Elaine Luo
- Daniel K. Inouye Center for Microbial Oceanography: Research and Education (C-MORE), University of Hawaii, Honolulu, HI, 96822, USA
| | - John M Eppley
- Daniel K. Inouye Center for Microbial Oceanography: Research and Education (C-MORE), University of Hawaii, Honolulu, HI, 96822, USA
| | - Anna E Romano
- Daniel K. Inouye Center for Microbial Oceanography: Research and Education (C-MORE), University of Hawaii, Honolulu, HI, 96822, USA
| | - Daniel R Mende
- Daniel K. Inouye Center for Microbial Oceanography: Research and Education (C-MORE), University of Hawaii, Honolulu, HI, 96822, USA
| | - Edward F DeLong
- Daniel K. Inouye Center for Microbial Oceanography: Research and Education (C-MORE), University of Hawaii, Honolulu, HI, 96822, USA.
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24
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Zimmerman AE, Bachy C, Ma X, Roux S, Jang HB, Sullivan MB, Waldbauer JR, Worden AZ. Closely related viruses of the marine picoeukaryotic alga Ostreococcus lucimarinus exhibit different ecological strategies. Environ Microbiol 2019; 21:2148-2170. [PMID: 30924271 PMCID: PMC6851583 DOI: 10.1111/1462-2920.14608] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2018] [Revised: 03/16/2019] [Accepted: 03/23/2019] [Indexed: 01/01/2023]
Abstract
In marine ecosystems, viruses are major disrupters of the direct flow of carbon and nutrients to higher trophic levels. Although the genetic diversity of several eukaryotic phytoplankton virus groups has been characterized, their infection dynamics are less understood, such that the physiological and ecological implications of their diversity remain unclear. We compared genomes and infection phenotypes of the two most closely related cultured phycodnaviruses infecting the widespread picoprasinophyte Ostreococcus lucimarinus under standard- (1.3 divisions per day) and limited-light (0.41 divisions per day) nutrient replete conditions. OlV7 infection caused early arrest of the host cell cycle, coinciding with a significantly higher proportion of infected cells than OlV1-amended treatments, regardless of host growth rate. OlV7 treatments showed a near-50-fold increase of progeny virions at the higher host growth rate, contrasting with OlV1's 16-fold increase. However, production of OlV7 virions was more sensitive than OlV1 production to reduced host growth rate, suggesting fitness trade-offs between infection efficiency and resilience to host physiology. Moreover, although organic matter released from OlV1- and OlV7-infected hosts had broadly similar chemical composition, some distinct molecular signatures were observed. Collectively, these results suggest that current views on viral relatedness through marker and core gene analyses underplay operational divergence and consequences for host ecology.
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Affiliation(s)
| | - Charles Bachy
- Monterey Bay Aquarium Research InstituteMoss LandingCAUSA
| | - Xiufeng Ma
- Department of the Geophysical SciencesUniversity of ChicagoChicagoILUSA
| | - Simon Roux
- Department of MicrobiologyEnvironmental and Geodetic Engineering, The Ohio State UniversityColumbusOHUSA
| | - Ho Bin Jang
- Department of MicrobiologyEnvironmental and Geodetic Engineering, The Ohio State UniversityColumbusOHUSA
- Department of CivilEnvironmental and Geodetic Engineering, The Ohio State UniversityColumbusOHUSA
| | - Matthew B. Sullivan
- Department of MicrobiologyEnvironmental and Geodetic Engineering, The Ohio State UniversityColumbusOHUSA
- Department of CivilEnvironmental and Geodetic Engineering, The Ohio State UniversityColumbusOHUSA
| | | | - Alexandra Z. Worden
- Monterey Bay Aquarium Research InstituteMoss LandingCAUSA
- Ocean EcoSystems Biology Unit, Marine Ecology DivisionGEOMAR Helmholtz Centre for Ocean Research KielKielDE
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25
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Systematic survey of non-retroviral virus-like elements in eukaryotic genomes. Virus Res 2019; 262:30-36. [DOI: 10.1016/j.virusres.2018.02.002] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2017] [Revised: 12/30/2017] [Accepted: 02/05/2018] [Indexed: 01/31/2023]
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26
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Viruses of Eukaryotic Algae: Diversity, Methods for Detection, and Future Directions. Viruses 2018; 10:v10090487. [PMID: 30208617 PMCID: PMC6165237 DOI: 10.3390/v10090487] [Citation(s) in RCA: 31] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2018] [Revised: 09/04/2018] [Accepted: 09/07/2018] [Indexed: 11/16/2022] Open
Abstract
The scope for ecological studies of eukaryotic algal viruses has greatly improved with the development of molecular and bioinformatic approaches that do not require algal cultures. Here, we review the history and perceived future opportunities for research on eukaryotic algal viruses. We begin with a summary of the 65 eukaryotic algal viruses that are presently in culture collections, with emphasis on shared evolutionary traits (e.g., conserved core genes) of each known viral type. We then describe how core genes have been used to enable molecular detection of viruses in the environment, ranging from PCR-based amplification to community scale "-omics" approaches. Special attention is given to recent studies that have employed network-analyses of -omics data to predict virus-host relationships, from which a general bioinformatics pipeline is described for this type of approach. Finally, we conclude with acknowledgement of how the field of aquatic virology is adapting to these advances, and highlight the need to properly characterize new virus-host systems that may be isolated using preliminary molecular surveys. Researchers can approach this work using lessons learned from the Chlorella virus system, which is not only the best characterized algal-virus system, but is also responsible for much of the foundation in the field of aquatic virology.
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27
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Bachy C, Charlesworth CJ, Chan AM, Finke JF, Wong CH, Wei CL, Sudek S, Coleman ML, Suttle CA, Worden AZ. Transcriptional responses of the marine green alga Micromonas pusilla and an infecting prasinovirus under different phosphate conditions. Environ Microbiol 2018; 20:2898-2912. [PMID: 29749714 DOI: 10.1111/1462-2920.14273] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2017] [Revised: 04/06/2018] [Accepted: 05/07/2018] [Indexed: 12/12/2022]
Abstract
Prasinophytes are widespread marine algae for which responses to nutrient limitation and viral infection are not well understood. We studied the picoprasinophyte, Micromonas pusilla, grown under phosphate-replete (0.65 ± 0.07 d-1 ) and 10-fold lower (low)-phosphate (0.11 ± 0.04 d-1 ) conditions, and infected by the phycodnavirus MpV-SP1. Expression of 17% of Micromonas genes in uninfected cells differed by >1.5-fold (q < 0.01) between nutrient conditions, with genes for P-metabolism and the uniquely-enriched Sel1-like repeat (SLR) family having higher relative transcript abundances, while phospholipid-synthesis genes were lower in low-P than P-replete. Approximately 70% (P-replete) and 30% (low-P) of cells were lysed 24 h post-infection, and expression of ≤5.8% of host genes changed relative to uninfected treatments. Host genes for CAZymes and glycolysis were activated by infection, supporting importance in viral production, which was significantly lower in slower growing (low-P) hosts. All MpV-SP1 genes were expressed, and our analyses suggest responses to differing host-phosphate backgrounds involve few viral genes, while the temporal program of infection involves many more, and is largely independent of host-phosphate background. Our study (i) identifies genes previously unassociated with nutrient acclimation or viral infection, (ii) provides insights into the temporal program of prasinovirus gene expression by hosts and (iii) establishes cell biological aspects of an ecologically important host-prasinovirus system that differ from other marine algal-virus systems.
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Affiliation(s)
- Charles Bachy
- Monterey Bay Aquarium Research Institute, Moss Landing, CA 95039, USA
| | - Christina J Charlesworth
- Department of Earth, Ocean and Atmospheric Sciences, University of British Columbia, Vancouver, BC V6T 1Z4, Canada
| | - Amy M Chan
- Department of Earth, Ocean and Atmospheric Sciences, University of British Columbia, Vancouver, BC V6T 1Z4, Canada
| | - Jan F Finke
- Department of Earth, Ocean and Atmospheric Sciences, University of British Columbia, Vancouver, BC V6T 1Z4, Canada
| | - Chee-Hong Wong
- Lawrence Berkeley National Laboratory, Sequencing Technology Group, Joint Genome Institute, Walnut Creek, CA 94598, USA
| | - Chia-Lin Wei
- Lawrence Berkeley National Laboratory, Sequencing Technology Group, Joint Genome Institute, Walnut Creek, CA 94598, USA
| | - Sebastian Sudek
- Monterey Bay Aquarium Research Institute, Moss Landing, CA 95039, USA
| | - Maureen L Coleman
- Department of the Geophysical Sciences, University of Chicago, Chicago, IL 60637, USA
| | - Curtis A Suttle
- Department of Earth, Ocean and Atmospheric Sciences, University of British Columbia, Vancouver, BC V6T 1Z4, Canada.,Integrated Microbial Biodiversity Program, Canadian Institute for Advanced Research, Toronto, M5G 1Z8, Canada.,Departments of Botany, and Microbiology & Immunology, and Institute of Oceans & Fisheries, University of British Columbia, Vancouver, BC V6T 1Z4, Canada
| | - Alexandra Z Worden
- Monterey Bay Aquarium Research Institute, Moss Landing, CA 95039, USA.,Integrated Microbial Biodiversity Program, Canadian Institute for Advanced Research, Toronto, M5G 1Z8, Canada
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28
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Yau S, Caravello G, Fonvieille N, Desgranges É, Moreau H, Grimsley N. Rapidity of Genomic Adaptations to Prasinovirus Infection in a Marine Microalga. Viruses 2018; 10:v10080441. [PMID: 30126244 PMCID: PMC6116238 DOI: 10.3390/v10080441] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2018] [Revised: 08/16/2018] [Accepted: 08/17/2018] [Indexed: 12/19/2022] Open
Abstract
Prasinoviruses are large dsDNA viruses commonly found in aquatic systems worldwide, where they can infect and lyse unicellular prasinophyte algae such as Ostreococcus. Host susceptibility is virus strain-specific, but resistance of susceptible Ostreococcus tauri strains to a virulent virus arises frequently. In clonal resistant lines that re-grow, viruses are usually present for many generations, and genes clustered on chromosome 19 show physical rearrangements and differential expression. Here, we investigated changes occurring during the first two weeks after inoculation of the prasinovirus OtV5. By serial dilutions of cultures at the time of inoculation, we estimated the frequency of resistant cells arising in virus-challenged O. tauri cultures to be 10-3⁻10-4 of the inoculated population. Re-growing resistant cells were detectable by flow cytometry 3 days post-inoculation (dpi), visible re-greening of cultures occurred by 6 dpi, and karyotypic changes were visually detectable at 8 dpi. Resistant cell lines showed a modified spectrum of host-virus specificities and much lower levels of OtV5 adsorption.
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Affiliation(s)
- Sheree Yau
- Integrative Biology of Marine Organisms Laboratory (BIOM), CNRS UMR7232, 66650 Banuyls-sur-Mer, France.
- Sorbonne University, OOB, Avenue de Pierre Fabre, 66650 Banyuls-sur-Mer, France.
| | - Gaëtan Caravello
- Integrative Biology of Marine Organisms Laboratory (BIOM), CNRS UMR7232, 66650 Banuyls-sur-Mer, France.
- Sorbonne University, OOB, Avenue de Pierre Fabre, 66650 Banyuls-sur-Mer, France.
| | - Nadège Fonvieille
- Integrative Biology of Marine Organisms Laboratory (BIOM), CNRS UMR7232, 66650 Banuyls-sur-Mer, France.
- Sorbonne University, OOB, Avenue de Pierre Fabre, 66650 Banyuls-sur-Mer, France.
| | - Élodie Desgranges
- Integrative Biology of Marine Organisms Laboratory (BIOM), CNRS UMR7232, 66650 Banuyls-sur-Mer, France.
- Sorbonne University, OOB, Avenue de Pierre Fabre, 66650 Banyuls-sur-Mer, France.
| | - Hervé Moreau
- Integrative Biology of Marine Organisms Laboratory (BIOM), CNRS UMR7232, 66650 Banuyls-sur-Mer, France.
- Sorbonne University, OOB, Avenue de Pierre Fabre, 66650 Banyuls-sur-Mer, France.
| | - Nigel Grimsley
- Integrative Biology of Marine Organisms Laboratory (BIOM), CNRS UMR7232, 66650 Banuyls-sur-Mer, France.
- Sorbonne University, OOB, Avenue de Pierre Fabre, 66650 Banyuls-sur-Mer, France.
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29
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Nishii K, Wright F, Chen YY, Möller M. Tangled history of a multigene family: The evolution of ISOPENTENYLTRANSFERASE genes. PLoS One 2018; 13:e0201198. [PMID: 30070990 PMCID: PMC6071968 DOI: 10.1371/journal.pone.0201198] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2017] [Accepted: 07/10/2018] [Indexed: 01/07/2023] Open
Abstract
ISOPENTENYLTRANSFERASE (IPT) genes play important roles in the initial steps of cytokinin synthesis, exist in plant and pathogenic bacteria, and form a multigene family in plants. Protein domain searches revealed that bacteria and plant IPT proteins were to assigned to different protein domains families in the Pfam database, namely Pfam IPT (IPTPfam) and Pfam IPPT (IPPTPfam) families, both are closely related in the P-loop NTPase clan. To understand the origin and evolution of the genes, a species matrix was assembled across the tree of life and intensively in plant lineages. The IPTPfam domain was only found in few bacteria lineages, whereas IPPTPfam is common except in Archaea and Mycoplasma bacteria. The bacterial IPPTPfam domain miaA genes were shown as ancestral of eukaryotic IPPTPfam domain genes. Plant IPTs diversified into class I, class II tRNA-IPTs, and Adenosine-phosphate IPTs; the class I tRNA-IPTs appeared to represent direct successors of miaA genes were found in all plant genomes, whereas class II tRNA-IPTs originated from eukaryotic genes, and were found in prasinophyte algae and in euphyllophytes. Adenosine-phosphate IPTs were only found in angiosperms. Gene duplications resulted in gene redundancies with ubiquitous expression or diversification in expression. In conclusion, it is shown that IPT genes have a complex history prior to the protein family split, and might have experienced losses or HGTs, and gene duplications that are to be likely correlated with the rise in morphological complexity involved in fine tuning cytokinin production.
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Affiliation(s)
- Kanae Nishii
- Royal Botanic Garden Edinburgh, Scotland, United Kingdom
- Tokyo Gakugei University, Koganei, Tokyo, Japan
- * E-mail: (KN); (MM)
| | - Frank Wright
- Biomathematics and Statistics Scotland, Edinburgh, Scotland, United Kingdom
| | - Yun-Yu Chen
- Royal Botanic Garden Edinburgh, Scotland, United Kingdom
- University of Edinburgh, Edinburgh, United Kingdom
| | - Michael Möller
- Royal Botanic Garden Edinburgh, Scotland, United Kingdom
- * E-mail: (KN); (MM)
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30
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Schvarcz CR, Steward GF. A giant virus infecting green algae encodes key fermentation genes. Virology 2018; 518:423-433. [PMID: 29649682 DOI: 10.1016/j.virol.2018.03.010] [Citation(s) in RCA: 62] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2017] [Revised: 03/08/2018] [Accepted: 03/11/2018] [Indexed: 11/29/2022]
Abstract
The family Mimiviridae contains uncommonly large viruses, many of which were isolated using a free-living amoeba as a host. Although the genomes of these and other mimivirids that infect marine heterokont and haptophyte protists have now been sequenced, there has yet to be a genomic investigation of a mimivirid that infects a member of the Viridiplantae lineage (green algae and land plants). Here we characterize the 668-kilobase complete genome of TetV-1, a mimivirid that infects the cosmopolitan green alga Tetraselmis (Chlorodendrophyceae). The analysis revealed genes not previously seen in viruses, such as the mannitol metabolism enzyme mannitol 1-phosphate dehydrogenase, the saccharide degradation enzyme alpha-galactosidase, and the key fermentation genes pyruvate formate-lyase and pyruvate formate-lyase activating enzyme. The TetV genome is the largest sequenced to date for a virus that infects a photosynthetic organism, and its genes reveal unprecedented mechanisms by which viruses manipulate their host's metabolism.
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Affiliation(s)
- Christopher R Schvarcz
- Department of Oceanography, Daniel K. Inouye Center for Microbial Oceanography: Research and Education, University of Hawai'i at Mānoa, 1950 East-West Road, Honolulu, HI 96822, United States
| | - Grieg F Steward
- Department of Oceanography, Daniel K. Inouye Center for Microbial Oceanography: Research and Education, University of Hawai'i at Mānoa, 1950 East-West Road, Honolulu, HI 96822, United States.
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31
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Prasinovirus Attack of Ostreococcus Is Furtive by Day but Savage by Night. J Virol 2018; 92:JVI.01703-17. [PMID: 29187539 PMCID: PMC5790953 DOI: 10.1128/jvi.01703-17] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2017] [Accepted: 11/09/2017] [Indexed: 12/12/2022] Open
Abstract
Prasinoviruses are large DNA viruses that infect diverse genera of green microalgae worldwide in aquatic ecosystems, but molecular knowledge of their life cycles is lacking. Several complete genomes of both these viruses and their marine algal hosts are now available and have been used to show the pervasive presence of these species in microbial metagenomes. We have analyzed the life cycle of Ostreococcus tauri virus 5 (OtV5), a lytic virus, using transcriptome sequencing (RNA-Seq) from 12 time points of healthy or infected Ostreococcus tauri cells over a day/night cycle in culture. In the day, viral gene transcription remained low while host nitrogen metabolism gene transcription was initially strongly repressed for two successive time points before being induced for 8 h, but during the night, viral transcription increased steeply while host nitrogen metabolism genes were repressed and many host functions that are normally reduced in the dark appeared to be compensated either by genes expressed from the virus or by increased expression of a subset of 4.4% of the host's genes. Some host cells underwent lysis progressively during the night, but a larger proportion were lysed the following morning. Our data suggest that the life cycles of algal viruses mirror the diurnal rhythms of their hosts.IMPORTANCE Prasinoviruses are common in marine environments, and although several complete genomes of these viruses and their hosts have been characterized, little is known about their life cycles. Here we analyze in detail the transcriptional changes occurring over a 27-h-long experiment in a natural diurnal rhythm, in which the growth of host cells is to some extent synchronized, so that host DNA replication occurs late in the day or early in the night and cell division occurs during the night. Surprisingly, viral transcription remains quiescent over the daytime, when the most energy (from light) is available, but during the night viral transcription activates, accompanied by expression of a few host genes that are probably required by the virus. Although our experiment was accomplished in the lab, cyclical changes have been documented in host transcription in the ocean. Our observations may thus be relevant for eukaryotic phytoplankton in natural environments.
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32
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Chen H, Zhang W, Li X, Pan Y, Yan S, Wang Y. The genome of a prasinoviruses-related freshwater virus reveals unusual diversity of phycodnaviruses. BMC Genomics 2018; 19:49. [PMID: 29334892 PMCID: PMC5769502 DOI: 10.1186/s12864-018-4432-4] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2017] [Accepted: 01/03/2018] [Indexed: 11/10/2022] Open
Abstract
Background Phycodnaviruses are widespread algae-infecting large dsDNA viruses and presently contain six genera: Chlorovirus, Prasinovirus, Prymnesiovirus, Phaeovirus, Coccolithovirus and Raphidovirus. The members in Prasinovirus are identified as marine viruses due to their marine algal hosts, while prasinovirus freshwater relatives remain rarely reported. Results Here we present the complete genomic sequence of a novel phycodnavirus, Dishui Lake Phycodnavirus 1 (DSLPV1), which was assembled from Dishui Lake metagenomic datasets. DSLPV1 harbors a linear genome of 181,035 bp in length (G + C content: 52.7%), with 227 predicted genes and 2 tRNA encoding regions. Both comparative genomic and phylogenetic analyses indicate that the freshwater algal virus DSLPV1 is closely related to the members in Prasinovirus, a group of marine algae infecting viruses. In addition, a complete eukaryotic histone H3 variant was identified in the genome of DSLPV1, which is firstly detected in phycodnaviruses and contributes to understand the interaction between algal virus and its eukaryotic hosts. Conclusion It is in a freshwater ecosystem that a novel Prasinovirus-related viral complete genomic sequence is discovered, which sheds new light on the evolution and diversity of the algae infecting Phycodnaviridae. Electronic supplementary material The online version of this article (10.1186/s12864-018-4432-4) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Hao Chen
- College of Food Science and Technology, Shanghai Ocean University, Shanghai, China
| | - Weijia Zhang
- College of Food Science and Technology, Shanghai Ocean University, Shanghai, China.,Present address: Archaea Center, Department of Biology, Copenhagen University, DK2000, Copenhagen, Denmark
| | - Xiefei Li
- College of Food Science and Technology, Shanghai Ocean University, Shanghai, China
| | - Yingjie Pan
- College of Food Science and Technology, Shanghai Ocean University, Shanghai, China.,Laboratory of Quality and Safety Risk Assessment for Aquatic Products on Storage and Preservation, Ministry of Agriculture, Shanghai, China
| | - Shuling Yan
- College of Food Science and Technology, Shanghai Ocean University, Shanghai, China.,Institute of Biochemistry and Molecular Cell Biology, University of Göttingen, Göttingen, Germany
| | - Yongjie Wang
- College of Food Science and Technology, Shanghai Ocean University, Shanghai, China. .,Laboratory for Marine Biology and Biotechnology, Qingdao National Laboratory for Marine Science and Technology, Qingdao, China. .,Laboratory of Quality and Safety Risk Assessment for Aquatic Products on Storage and Preservation, Ministry of Agriculture, Shanghai, China.
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33
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Host-derived viral transporter protein for nitrogen uptake in infected marine phytoplankton. Proc Natl Acad Sci U S A 2017; 114:E7489-E7498. [PMID: 28827361 DOI: 10.1073/pnas.1708097114] [Citation(s) in RCA: 51] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Phytoplankton community structure is shaped by both bottom-up factors, such as nutrient availability, and top-down processes, such as predation. Here we show that marine viruses can blur these distinctions, being able to amend how host cells acquire nutrients from their environment while also predating and lysing their algal hosts. Viral genomes often encode genes derived from their host. These genes may allow the virus to manipulate host metabolism to improve viral fitness. We identify in the genome of a phytoplankton virus, which infects the small green alga Ostreococcus tauri, a host-derived ammonium transporter. This gene is transcribed during infection and when expressed in yeast mutants the viral protein is located to the plasma membrane and rescues growth when cultured with ammonium as the sole nitrogen source. We also show that viral infection alters the nature of nitrogen compound uptake of host cells, by both increasing substrate affinity and allowing the host to access diverse nitrogen sources. This is important because the availability of nitrogen often limits phytoplankton growth. Collectively, these data show that a virus can acquire genes encoding nutrient transporters from a host genome and that expression of the viral gene can alter the nutrient uptake behavior of host cells. These results have implications for understanding how viruses manipulate the physiology and ecology of phytoplankton, influence marine nutrient cycles, and act as vectors for horizontal gene transfer.
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34
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Joli N, Monier A, Logares R, Lovejoy C. Seasonal patterns in Arctic prasinophytes and inferred ecology of Bathycoccus unveiled in an Arctic winter metagenome. THE ISME JOURNAL 2017; 11:1372-1385. [PMID: 28267153 PMCID: PMC5437359 DOI: 10.1038/ismej.2017.7] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/05/2016] [Revised: 12/04/2016] [Accepted: 01/09/2017] [Indexed: 11/09/2022]
Abstract
Prasinophytes occur in all oceans but rarely dominate phytoplankton populations. In contrast, a single ecotype of the prasinophyte Micromonas is frequently the most abundant photosynthetic taxon reported in the Arctic from summer through autumn. However, seasonal dynamics of prasinophytes outside of this period are little known. To address this, we analyzed high-throughput V4 18S rRNA amplicon data collected from November to July in the Amundsen Gulf Region, Beaufort Sea, Arctic. Surprisingly during polar sunset in November and December, we found a high proportion of reads from both DNA and RNA belonging to another prasinophyte, Bathycoccus. We then analyzed a metagenome from a December sample and the resulting Bathycoccus metagenome assembled genome (MAG) covered ~90% of the Bathycoccus Ban7 reference genome. In contrast, only ~20% of a reference Micromonas genome was found in the metagenome. Our phylogenetic analysis of marker genes placed the Arctic Bathycoccus in the B1 coastal clade. In addition, substitution rates of 129 coding DNA sequences were ~1.6% divergent between the Arctic MAG and coastal Chilean upwelling MAGs and 17.3% between it and a South East Atlantic open ocean MAG in the B2 Clade. The metagenomic analysis also revealed a winter viral community highly skewed toward viruses targeting Micromonas, with a much lower diversity of viruses targeting Bathycoccus. Overall a combination of Micromonas being relatively less able to maintain activity under dark winter conditions and viral suppression of Micromonas may have contributed to the success of Bathycoccus in the Amundsen Gulf during winter.
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Affiliation(s)
- Nathalie Joli
- Département de Biologie, Institut de Biologie Intégrative et des Systèmes, Québec Océan, Université Laval, Québec City, QC, Canada
- Takuvik Joint International Laboratory, Centre National de la Recherche Scientifique (France, CNRS UMI 3376), Université Laval, Québec City, QC, Canada
| | - Adam Monier
- School of Biosciences, College of Life and Environmental Sciences, University of Exeter, Exeter, UK
| | - Ramiro Logares
- Department of Marine Biology and Oceanography, Institut de Ciències del Mar (CSIC), Barcelona, Spain
| | - Connie Lovejoy
- Département de Biologie, Institut de Biologie Intégrative et des Systèmes, Québec Océan, Université Laval, Québec City, QC, Canada
- Takuvik Joint International Laboratory, Centre National de la Recherche Scientifique (France, CNRS UMI 3376), Université Laval, Québec City, QC, Canada
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Variation in the Genetic Repertoire of Viruses Infecting Micromonas pusilla Reflects Horizontal Gene Transfer and Links to Their Environmental Distribution. Viruses 2017; 9:v9050116. [PMID: 28534829 PMCID: PMC5454428 DOI: 10.3390/v9050116] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2017] [Revised: 05/08/2017] [Accepted: 05/10/2017] [Indexed: 11/17/2022] Open
Abstract
Prasinophytes, a group of eukaryotic phytoplankton, has a global distribution and is infected by large double-stranded DNA viruses (prasinoviruses) in the family Phycodnaviridae. This study examines the genetic repertoire, phylogeny, and environmental distribution of phycodnaviruses infecting Micromonas pusilla, other prasinophytes and chlorophytes. Based on comparisons among the genomes of viruses infecting M. pusilla and other phycodnaviruses, as well as the genome from a host isolate of M. pusilla, viruses infecting M. pusilla (MpVs) share a limited set of core genes, but vary strongly in their flexible pan-genome that includes numerous metabolic genes, such as those associated with amino acid synthesis and sugar manipulation. Surprisingly, few of these presumably host-derived genes are shared with M. pusilla, but rather have their closest non-viral homologue in bacteria and other eukaryotes, indicating horizontal gene transfer. A comparative analysis of full-length DNA polymerase (DNApol) genes from prasinoviruses with their overall gene content, demonstrated that the phylogeny of DNApol gene fragments reflects the gene content of the viruses; hence, environmental DNApol gene sequences from prasinoviruses can be used to infer their overall genetic repertoire. Thus, the distribution of virus ecotypes across environmental samples based on DNApol sequences implies substantial underlying differences in gene content that reflect local environmental conditions. Moreover, the high diversity observed in the genetic repertoire of prasinoviruses has been driven by horizontal gene transfer throughout their evolutionary history, resulting in a broad suite of functional capabilities and a high diversity of prasinovirus ecotypes.
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Van Etten JL, Agarkova I, Dunigan DD, Tonetti M, De Castro C, Duncan GA. Chloroviruses Have a Sweet Tooth. Viruses 2017; 9:E88. [PMID: 28441734 PMCID: PMC5408694 DOI: 10.3390/v9040088] [Citation(s) in RCA: 30] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2017] [Revised: 04/13/2017] [Accepted: 04/14/2017] [Indexed: 01/16/2023] Open
Abstract
Chloroviruses are large double-stranded DNA (dsDNA) viruses that infect certain isolates of chlorella-like green algae. They contain up to approximately 400 protein-encoding genes and 16 transfer RNA (tRNA) genes. This review summarizes the unexpected finding that many of the chlorovirus genes encode proteins involved in manipulating carbohydrates. These include enzymes involved in making extracellular polysaccharides, such as hyaluronan and chitin, enzymes that make nucleotide sugars, such as GDP-L-fucose and GDP-D-rhamnose and enzymes involved in the synthesis of glycans attached to the virus major capsid proteins. This latter process differs from that of all other glycoprotein containing viruses that traditionally use the host endoplasmic reticulum and Golgi machinery to synthesize and transfer the glycans.
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Affiliation(s)
- James L Van Etten
- Department of Plant Pathology and Nebraska Center for Virology, University of Nebraska-Lincoln, Lincoln, NE 68583-0900, USA.
| | - Irina Agarkova
- Department of Plant Pathology and Nebraska Center for Virology, University of Nebraska-Lincoln, Lincoln, NE 68583-0900, USA.
| | - David D Dunigan
- Department of Plant Pathology and Nebraska Center for Virology, University of Nebraska-Lincoln, Lincoln, NE 68583-0900, USA.
| | - Michela Tonetti
- Department of Experimental Medicine and Center of Excellence for Biomedical Research, University of Genova Viale Benedetto XV/1, 16132 Genova, Italy.
| | - Christina De Castro
- Department of Agricultural Sciences, University of Napoli, Via Università 100, 80055 Portici, NA, Italy.
| | - Garry A Duncan
- Department of Biology, Nebraska Wesleyan University, Lincoln, NE 68504-2796, USA.
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Weynberg KD, Allen MJ, Wilson WH. Marine Prasinoviruses and Their Tiny Plankton Hosts: A Review. Viruses 2017; 9:E43. [PMID: 28294997 PMCID: PMC5371798 DOI: 10.3390/v9030043] [Citation(s) in RCA: 36] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2017] [Revised: 03/04/2017] [Accepted: 03/08/2017] [Indexed: 12/29/2022] Open
Abstract
Viruses play a crucial role in the marine environment, promoting nutrient recycling and biogeochemical cycling and driving evolutionary processes. Tiny marine phytoplankton called prasinophytes are ubiquitous and significant contributors to global primary production and biomass. A number of viruses (known as prasinoviruses) that infect these important primary producers have been isolated and characterised over the past decade. Here we review the current body of knowledge about prasinoviruses and their interactions with their algal hosts. Several genes, including those encoding for glycosyltransferases, methyltransferases and amino acid synthesis enzymes, which have never been identified in viruses of eukaryotes previously, have been detected in prasinovirus genomes. The host organisms are also intriguing; most recently, an immunity chromosome used by a prasinophyte in response to viral infection was discovered. In light of such recent, novel discoveries, we discuss why the cellular simplicity of prasinophytes makes for appealing model host organism-virus systems to facilitate focused and detailed investigations into the dynamics of marine viruses and their intimate associations with host species. We encourage the adoption of the prasinophyte Ostreococcus and its associated viruses as a model host-virus system for examination of cellular and molecular processes in the marine environment.
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Affiliation(s)
- Karen D Weynberg
- Australian Institute of Marine Science, PMB 3, Townsville, Queensland 4810, Australia.
| | - Michael J Allen
- Plymouth Marine Laboratory, Prospect Place, Plymouth PL1 3DH, UK.
| | - William H Wilson
- Sir Alister Hardy Foundation for Ocean Science, The Laboratory, Citadel Hill, Plymouth PL1 2PB, UK.
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Yau S, Hemon C, Derelle E, Moreau H, Piganeau G, Grimsley N. A Viral Immunity Chromosome in the Marine Picoeukaryote, Ostreococcus tauri. PLoS Pathog 2016; 12:e1005965. [PMID: 27788272 PMCID: PMC5082852 DOI: 10.1371/journal.ppat.1005965] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2016] [Accepted: 09/29/2016] [Indexed: 12/22/2022] Open
Abstract
Micro-algae of the genus Ostreococcus and related species of the order Mamiellales are globally distributed in the photic zone of world's oceans where they contribute to fixation of atmospheric carbon and production of oxygen, besides providing a primary source of nutrition in the food web. Their tiny size, simple cells, ease of culture, compact genomes and susceptibility to the most abundant large DNA viruses in the sea render them attractive as models for integrative marine biology. In culture, spontaneous resistance to viruses occurs frequently. Here, we show that virus-producing resistant cell lines arise in many independent cell lines during lytic infections, but over two years, more and more of these lines stop producing viruses. We observed sweeping over-expression of all genes in more than half of chromosome 19 in resistant lines, and karyotypic analyses showed physical rearrangements of this chromosome. Chromosome 19 has an unusual genetic structure whose equivalent is found in all of the sequenced genomes in this ecologically important group of green algae. We propose that chromosome 19 of O. tauri is specialized in defence against viral attack, a constant threat for all planktonic life, and that the most likely cause of resistance is the over-expression of numerous predicted glycosyltransferase genes. O. tauri thus provides an amenable model for molecular analysis of genome evolution under environmental stress and for investigating glycan-mediated host-virus interactions, such as those seen in herpes, influenza, HIV, PBCV and mimivirus.
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Affiliation(s)
- Sheree Yau
- Sorbonne Universités, UPMC Univ Paris 06, CNRS, Biologie Intégrative des Organismes Marins (BIOM, UMR 7232), Observatoire Océanologique, Banyuls sur Mer, France
| | - Claire Hemon
- Sorbonne Universités, UPMC Univ Paris 06, CNRS, Biologie Intégrative des Organismes Marins (BIOM, UMR 7232), Observatoire Océanologique, Banyuls sur Mer, France
| | - Evelyne Derelle
- Sorbonne Universités, UPMC Univ Paris 06, CNRS, Biologie Intégrative des Organismes Marins (BIOM, UMR 7232), Observatoire Océanologique, Banyuls sur Mer, France
| | - Hervé Moreau
- Sorbonne Universités, UPMC Univ Paris 06, CNRS, Biologie Intégrative des Organismes Marins (BIOM, UMR 7232), Observatoire Océanologique, Banyuls sur Mer, France
| | - Gwenaël Piganeau
- Sorbonne Universités, UPMC Univ Paris 06, CNRS, Biologie Intégrative des Organismes Marins (BIOM, UMR 7232), Observatoire Océanologique, Banyuls sur Mer, France
| | - Nigel Grimsley
- Sorbonne Universités, UPMC Univ Paris 06, CNRS, Biologie Intégrative des Organismes Marins (BIOM, UMR 7232), Observatoire Océanologique, Banyuls sur Mer, France
- * E-mail:
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Rousvoal S, Bouyer B, López-Cristoffanini C, Boyen C, Collén J. Mutant swarms of a totivirus-like entities are present in the red macroalga Chondrus crispus and have been partially transferred to the nuclear genome. JOURNAL OF PHYCOLOGY 2016; 52:493-504. [PMID: 27151076 DOI: 10.1111/jpy.12427] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/20/2016] [Accepted: 03/15/2016] [Indexed: 06/05/2023]
Abstract
Chondrus crispus Stackhouse (Gigartinales) is a red seaweed found on North Atlantic rocky shores. Electrophoresis of RNA extracts showed a prominent band with a size of around 6,000 bp. Sequencing of the band revealed several sequences with similarity to totiviruses, double-stranded RNA viruses that normally infect fungi. This virus-like entity was named C. crispus virus (CcV). It should probably be regarded as an extreme viral quasispecies or a mutant swarm since low identity (<65%) was found between sequences. Totiviruses typically code for two genes: one capsid gene (gag) and one RNA-dependent RNA polymerase gene (pol) with a pseudoknot structure between the genes. Both the genes and the intergenic structures were found in the CcV sequences. A nonidentical gag gene was also found in the nuclear genome of C. crispus, with associated expressed sequence tags (EST) and upstream regulatory features. The gene was presumably horizontally transferred from the virus to the alga. Similar dsRNA bands were seen in extracts from different life cycle stages of C. crispus and from all geographic locations tested. In addition, similar bands were also observed in RNA extractions from other red algae; however, the significance of this apparently widespread phenomenon is unknown. Neither phenotype caused by the infection nor any virus particles or capsid proteins were identified; thus, the presence of viral particles has not been validated. These findings increase the known host range of totiviruses to include marine red algae.
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Affiliation(s)
- Sylvie Rousvoal
- CNRS, UMR 8227, Integrative Biology of Marine Models, Station Biologique de Roscoff, CS 90074, 29688, Roscoff Cedex, France
- UMR 8227, Integrative Biology of Marine Models, Station Biologique de Roscoff, Sorbonne Universités, UPMC Univ Paris 06, CS 90074, 29688, Roscoff Cedex, France
| | - Betty Bouyer
- CNRS, UMR 8227, Integrative Biology of Marine Models, Station Biologique de Roscoff, CS 90074, 29688, Roscoff Cedex, France
- UMR 8227, Integrative Biology of Marine Models, Station Biologique de Roscoff, Sorbonne Universités, UPMC Univ Paris 06, CS 90074, 29688, Roscoff Cedex, France
| | - Camilo López-Cristoffanini
- CNRS, UMR 8227, Integrative Biology of Marine Models, Station Biologique de Roscoff, CS 90074, 29688, Roscoff Cedex, France
- UMR 8227, Integrative Biology of Marine Models, Station Biologique de Roscoff, Sorbonne Universités, UPMC Univ Paris 06, CS 90074, 29688, Roscoff Cedex, France
| | - Catherine Boyen
- CNRS, UMR 8227, Integrative Biology of Marine Models, Station Biologique de Roscoff, CS 90074, 29688, Roscoff Cedex, France
- UMR 8227, Integrative Biology of Marine Models, Station Biologique de Roscoff, Sorbonne Universités, UPMC Univ Paris 06, CS 90074, 29688, Roscoff Cedex, France
| | - Jonas Collén
- CNRS, UMR 8227, Integrative Biology of Marine Models, Station Biologique de Roscoff, CS 90074, 29688, Roscoff Cedex, France
- UMR 8227, Integrative Biology of Marine Models, Station Biologique de Roscoff, Sorbonne Universités, UPMC Univ Paris 06, CS 90074, 29688, Roscoff Cedex, France
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40
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The Autonomous Glycosylation of Large DNA Viruses. Int J Mol Sci 2015; 16:29315-28. [PMID: 26690138 PMCID: PMC4691112 DOI: 10.3390/ijms161226169] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2015] [Revised: 12/01/2015] [Accepted: 12/01/2015] [Indexed: 11/17/2022] Open
Abstract
Glycosylation of surface molecules is a key feature of several eukaryotic viruses, which use the host endoplasmic reticulum/Golgi apparatus to add carbohydrates to their nascent glycoproteins. In recent years, a newly discovered group of eukaryotic viruses, belonging to the Nucleo-Cytoplasmic Large DNA Virus (NCLDV) group, was shown to have several features that are typical of cellular organisms, including the presence of components of the glycosylation machinery. Starting from initial observations with the chlorovirus PBCV-1, enzymes for glycan biosynthesis have been later identified in other viruses; in particular in members of the Mimiviridae family. They include both the glycosyltransferases and other carbohydrate-modifying enzymes and the pathways for the biosynthesis of the rare monosaccharides that are found in the viral glycan structures. These findings, together with genome analysis of the newly-identified giant DNA viruses, indicate that the presence of glycogenes is widespread in several NCLDV families. The identification of autonomous viral glycosylation machinery leads to many questions about the origin of these pathways, the mechanisms of glycan production, and eventually their function in the viral replication cycle. The scope of this review is to highlight some of the recent results that have been obtained on the glycosylation systems of the large DNA viruses, with a special focus on the enzymes involved in nucleotide-sugar production.
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The 474-Kilobase-Pair Complete Genome Sequence of CeV-01B, a Virus Infecting Haptolina (Chrysochromulina) ericina (Prymnesiophyceae). GENOME ANNOUNCEMENTS 2015; 3:3/6/e01413-15. [PMID: 26634761 PMCID: PMC4669402 DOI: 10.1128/genomea.01413-15] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Indexed: 12/03/2022]
Abstract
We report the complete genome sequence of CeV-01B, a large double-stranded DNA virus infecting the unicellular marine phytoplankton Haptolina (formerly Chrysochromulina) ericina. CeV-01B and its closest relative Phaeocystis globosa virus define an emerging subclade of the Megaviridae family with smaller genomes and particles than the originally described giant Mimiviridae infecting Acanthamoeba.
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42
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Zhang W, Zhou J, Liu T, Yu Y, Pan Y, Yan S, Wang Y. Four novel algal virus genomes discovered from Yellowstone Lake metagenomes. Sci Rep 2015; 5:15131. [PMID: 26459929 PMCID: PMC4602308 DOI: 10.1038/srep15131] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2015] [Accepted: 09/17/2015] [Indexed: 11/09/2022] Open
Abstract
Phycodnaviruses are algae-infecting large dsDNA viruses that are widely distributed in aquatic environments. Here, partial genomic sequences of four novel algal viruses were assembled from a Yellowstone Lake metagenomic data set. Genomic analyses revealed that three Yellowstone Lake phycodnaviruses (YSLPVs) had genome lengths of 178,262 bp, 171,045 bp, and 171,454 bp, respectively, and were phylogenetically closely related to prasinoviruses (Phycodnaviridae). The fourth (YSLGV), with a genome length of 73,689 bp, was related to group III in the extended family Mimiviridae comprising Organic Lake phycodnaviruses and Phaeocystis globosa virus 16 T (OLPG). A pair of inverted terminal repeats was detected in YSLPV1, suggesting that its genome is nearly complete. Interestingly, these four putative YSL giant viruses also bear some genetic similarities to Yellowstone Lake virophages (YSLVs). For example, they share nine non-redundant homologous genes, including ribonucleotide reductase small subunit (a gene conserved in nucleo-cytoplasmic large DNA viruses) and Organic Lake virophage OLV2 (conserved in the majority of YSLVs). Additionally, putative multidrug resistance genes (emrE) were found in YSLPV1 and YSLPV2 but not in other viruses. Phylogenetic trees of emrE grouped YSLPVs with algae, suggesting that horizontal gene transfer occurred between giant viruses and their potential algal hosts.
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Affiliation(s)
- Weijia Zhang
- College of Food Science and Technology, Shanghai Ocean University, Shanghai, China
| | - Jinglie Zhou
- College of Food Science and Technology, Shanghai Ocean University, Shanghai, China.,Department of Biological Sciences, Auburn University, Auburn, AL, USA
| | - Taigang Liu
- College of Information Technology, Shanghai Ocean University, Shanghai, China
| | - Yongxin Yu
- College of Food Science and Technology, Shanghai Ocean University, Shanghai, China.,Laboratory of Quality and Safety Risk Assessment for Aquatic Products on Storage &Preservation, Ministry of Agriculture, Shanghai, China
| | - Yingjie Pan
- College of Food Science and Technology, Shanghai Ocean University, Shanghai, China.,Laboratory of Quality and Safety Risk Assessment for Aquatic Products on Storage &Preservation, Ministry of Agriculture, Shanghai, China
| | - Shuling Yan
- College of Food Science and Technology, Shanghai Ocean University, Shanghai, China.,Institute of Biochemistry and Molecular Cell Biology, University of Göttingen, Göttingen, Germany
| | - Yongjie Wang
- College of Food Science and Technology, Shanghai Ocean University, Shanghai, China.,Laboratory of Quality and Safety Risk Assessment for Aquatic Products on Storage &Preservation, Ministry of Agriculture, Shanghai, China
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Goldsmith DB, Parsons RJ, Beyene D, Salamon P, Breitbart M. Deep sequencing of the viral phoH gene reveals temporal variation, depth-specific composition, and persistent dominance of the same viral phoH genes in the Sargasso Sea. PeerJ 2015; 3:e997. [PMID: 26157645 PMCID: PMC4476143 DOI: 10.7717/peerj.997] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2015] [Accepted: 05/13/2015] [Indexed: 11/20/2022] Open
Abstract
Deep sequencing of the viral phoH gene, a host-derived auxiliary metabolic gene, was used to track viral diversity throughout the water column at the Bermuda Atlantic Time-series Study (BATS) site in the summer (September) and winter (March) of three years. Viral phoH sequences reveal differences in the viral communities throughout a depth profile and between seasons in the same year. Variation was also detected between the same seasons in subsequent years, though these differences were not as great as the summer/winter distinctions. Over 3,600 phoH operational taxonomic units (OTUs; 97% sequence identity) were identified. Despite high richness, most phoH sequences belong to a few large, common OTUs whereas the majority of the OTUs are small and rare. While many OTUs make sporadic appearances at just a few times or depths, a small number of OTUs dominate the community throughout the seasons, depths, and years.
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Affiliation(s)
- Dawn B Goldsmith
- College of Marine Science, University of South Florida , St. Petersburg, FL , USA
| | | | - Damitu Beyene
- Department of Mathematics and Statistics, San Diego State University , San Diego, CA , USA
| | - Peter Salamon
- Department of Mathematics and Statistics, San Diego State University , San Diego, CA , USA
| | - Mya Breitbart
- College of Marine Science, University of South Florida , St. Petersburg, FL , USA
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44
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Diversity of Viruses Infecting the Green Microalga Ostreococcus lucimarinus. J Virol 2015; 89:5812-21. [PMID: 25787287 DOI: 10.1128/jvi.00246-15] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2015] [Accepted: 03/06/2015] [Indexed: 01/10/2023] Open
Abstract
UNLABELLED The functional diversity of eukaryotic viruses infecting a single host strain from seawater samples originating from distant marine locations is unknown. To estimate this diversity, we used lysis plaque assays to detect viruses that infect the widespread species Ostreococcus lucimarinus, which is found in coastal and mesotrophic systems, and O. tauri, which was isolated from coastal and lagoon sites from the northwest Mediterranean Sea. Detection of viral lytic activities against O. tauri was not observed using seawater from most sites, except those close to the area where the host strain was isolated. In contrast, the more cosmopolitan O. lucimarinus species recovered viruses from locations in the Atlantic and Pacific Oceans and the Mediterranean Sea. Six new O. lucimarinus viruses (OlVs) then were characterized and their genomes sequenced. Two subgroups of OlVs were distinguished based on their genetic distances and on the inversion of a central 32-kb-long DNA fragment, but overall their genomes displayed a high level of synteny. The two groups did not correspond to proximity of isolation sites, and the phylogenetic distance between these subgroups was higher than the distances observed among viruses infecting O. tauri. Our study demonstrates that viruses originating from very distant sites are able to infect the same algal host strain and can be more diverse than those infecting different species of the same genus. Finally, distinctive features and evolutionary distances between these different viral subgroups does not appear to be linked to biogeography of the viral isolates. IMPORTANCE Marine eukaryotic phytoplankton virus diversity has yet to be addressed, and more specifically, it is unclear whether diversity is connected to geographical distance and whether differential infection and lysis patterns exist among such viruses that infect the same host strain. Here, we assessed the genetic distance of geographically segregated viruses that infect the ubiquitous green microalga Ostreococcus. This study provides the first glimpse into the diversity of predicted gene functions in Ostreococcus viruses originating from distant sites and provides new insights into potential host distributions and restrictions in the world oceans.
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Johannessen TV, Bratbak G, Larsen A, Ogata H, Egge ES, Edvardsen B, Eikrem W, Sandaa RA. Characterisation of three novel giant viruses reveals huge diversity among viruses infecting Prymnesiales (Haptophyta). Virology 2015; 476:180-188. [DOI: 10.1016/j.virol.2014.12.014] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2014] [Revised: 11/13/2014] [Accepted: 12/08/2014] [Indexed: 01/05/2023]
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Siotto F, Martin C, Rauh O, Van Etten JL, Schroeder I, Moroni A, Thiel G. Viruses infecting marine picoplancton encode functional potassium ion channels. Virology 2014; 466-467:103-11. [PMID: 25441713 DOI: 10.1016/j.virol.2014.05.002] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2014] [Revised: 04/29/2014] [Accepted: 05/03/2014] [Indexed: 01/19/2023]
Abstract
Phycodnaviruses are dsDNA viruses, which infect algae. Their large genomes encode many gene products, like small K(+) channels, with homologs in prokaryotes and eukaryotes. Screening for K(+) channels revealed their abundance in viruses from fresh-water habitats. Recent sequencing of viruses from marine algae or from salt water in Antarctica revealed sequences with the predicted characteristics of K(+) channels but with some unexpected features. Two genes encode either 78 or 79 amino acid proteins, which are the smallest known K(+) channels. Also of interest is an unusual sequence in the canonical α-helixes in K(+) channels. Structural prediction algorithms indicate that the new channels have the conserved α-helix folds but the algorithms failed to identify the expected transmembrane domains flanking the K(+) channel pores. In spite of these unexpected properties electophysiological studies confirmed that the new proteins are functional K(+) channels.
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Affiliation(s)
- Fenja Siotto
- Membrane Biophysics Group, Dept. of Biology, Technical University Darmstadt, Germany
| | - Corinna Martin
- Membrane Biophysics Group, Dept. of Biology, Technical University Darmstadt, Germany
| | - Oliver Rauh
- Membrane Biophysics Group, Dept. of Biology, Technical University Darmstadt, Germany
| | - James L Van Etten
- Department of Plant Pathology and Nebraska Center for Virology, University of Nebraska, Lincoln, NE 68583-0900, USA
| | - Indra Schroeder
- Membrane Biophysics Group, Dept. of Biology, Technical University Darmstadt, Germany
| | - Anna Moroni
- Dipartimento di Biologia Università degli Studi di Milano e Istituto di Biofisica, CNR, Milano, Italy
| | - Gerhard Thiel
- Membrane Biophysics Group, Dept. of Biology, Technical University Darmstadt, Germany.
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47
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Mozar M, Claverie JM. Expanding the Mimiviridae family using asparagine synthase as a sequence bait. Virology 2014; 466-467:112-22. [DOI: 10.1016/j.virol.2014.05.013] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2014] [Revised: 05/05/2014] [Accepted: 05/10/2014] [Indexed: 12/23/2022]
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Clerissi C, Grimsley N, Subirana L, Maria E, Oriol L, Ogata H, Moreau H, Desdevises Y. Prasinovirus distribution in the Northwest Mediterranean Sea is affected by the environment and particularly by phosphate availability. Virology 2014; 466-467:146-57. [PMID: 25109909 DOI: 10.1016/j.virol.2014.07.016] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2014] [Revised: 05/13/2014] [Accepted: 07/08/2014] [Indexed: 10/24/2022]
Abstract
Numerous seawater lagoons punctuate the southern coastline of France. Exchanges of seawater between these lagoons and the open sea are limited by narrow channels connecting them. Lagoon salinities vary according to evaporation and to the volume of freshwater arriving from influent streams, whose nutrients also promote the growth of algae. We compared Prasinovirus communities, whose replication is supported by microscopic green algae, in four lagoons and at a coastal sampling site. Using high-throughput sequencing of DNA from a giant virus-specific marker gene, we show that the environmental conditions significantly affect the types of detectable viruses across samples. In spatial comparisons between 5 different sampling sites, higher levels of phosphates, nitrates, nitrites, ammonium and silicates tend to increase viral community richness independently of geographical distances between the sampling sites. Finally, comparisons of Prasinovirus communities at 2 sampling sites over a period of 10 months highlighted seasonal effects and the preponderant nature of phosphate concentrations in constraining viral distribution.
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Affiliation(s)
- Camille Clerissi
- Sorbonne Universités, UPMC Univ Paris 06, UMR 7232, Biologie Intégrative des Organismes Marin, Observatoire Océanologique, Avenue du Fontaulé, F-66650 Banyuls-sur-Mer, France; Sorbonne Universités, CNRS, UMR 7232, Observatoire Océanologique, Biologie Intégrative des Organismes Marins, Avenue du Fontaulé, F-66650 Banyuls-sur-Mer, France
| | - Nigel Grimsley
- Sorbonne Universités, UPMC Univ Paris 06, UMR 7232, Biologie Intégrative des Organismes Marin, Observatoire Océanologique, Avenue du Fontaulé, F-66650 Banyuls-sur-Mer, France; Sorbonne Universités, CNRS, UMR 7232, Observatoire Océanologique, Biologie Intégrative des Organismes Marins, Avenue du Fontaulé, F-66650 Banyuls-sur-Mer, France.
| | - Lucie Subirana
- Sorbonne Universités, UPMC Univ Paris 06, UMR 7232, Biologie Intégrative des Organismes Marin, Observatoire Océanologique, Avenue du Fontaulé, F-66650 Banyuls-sur-Mer, France; Sorbonne Universités, CNRS, UMR 7232, Observatoire Océanologique, Biologie Intégrative des Organismes Marins, Avenue du Fontaulé, F-66650 Banyuls-sur-Mer, France
| | - Eric Maria
- Sorbonne Universités, UPMC Univ Paris 06, UMS 2348, Observatoire Océanologique, Avenue du Fontaulé, F-66650 Banyuls-sur-Mer, France
| | - Louise Oriol
- Sorbonne Universités, UPMC Univ Paris 06, UMR 7621, Laboratoire d׳Océanographie Microbienne, Observatoire Océanologique, Avenue du Fontaulé, F-66650 Banyuls-sur-Mer, France; Sorbonne Universités, CNRS, UMR 7621, Observatoire Océanologique, Laboratoire d׳Océanographie Microbienne, Avenue du Fontaulé, F-66650 Banyuls-sur-Mer, France
| | - Hiroyuki Ogata
- Institute for Chemical Research, Kyoto University, Uji, Kyoto 611-0011, Japan
| | - Hervé Moreau
- Sorbonne Universités, UPMC Univ Paris 06, UMR 7232, Biologie Intégrative des Organismes Marin, Observatoire Océanologique, Avenue du Fontaulé, F-66650 Banyuls-sur-Mer, France; Sorbonne Universités, CNRS, UMR 7232, Observatoire Océanologique, Biologie Intégrative des Organismes Marins, Avenue du Fontaulé, F-66650 Banyuls-sur-Mer, France
| | - Yves Desdevises
- Sorbonne Universités, UPMC Univ Paris 06, UMR 7232, Biologie Intégrative des Organismes Marin, Observatoire Océanologique, Avenue du Fontaulé, F-66650 Banyuls-sur-Mer, France; Sorbonne Universités, CNRS, UMR 7232, Observatoire Océanologique, Biologie Intégrative des Organismes Marins, Avenue du Fontaulé, F-66650 Banyuls-sur-Mer, France
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Moniruzzaman M, LeCleir GR, Brown CM, Gobler CJ, Bidle KD, Wilson WH, Wilhelm SW. Genome of brown tide virus (AaV), the little giant of the Megaviridae, elucidates NCLDV genome expansion and host-virus coevolution. Virology 2014; 466-467:60-70. [PMID: 25035289 DOI: 10.1016/j.virol.2014.06.031] [Citation(s) in RCA: 68] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2014] [Revised: 06/19/2014] [Accepted: 06/21/2014] [Indexed: 10/25/2022]
Abstract
Aureococcus anophagefferens causes economically and ecologically destructive "brown tides" in the United States, China and South Africa. Here we report the 370,920bp genomic sequence of AaV, a virus capable of infecting and lysing A. anophagefferens. AaV is a member of the nucleocytoplasmic large DNA virus (NCLDV) group, harboring 377 putative coding sequences and 8 tRNAs. Despite being an algal virus, AaV shows no phylogenetic affinity to the Phycodnaviridae family, to which most algae-infecting viruses belong. Core gene phylogenies, shared gene content and genome-wide similarities suggest AaV is the smallest member of the emerging clade "Megaviridae". The genomic architecture of AaV demonstrates that the ancestral virus had an even smaller genome, which expanded through gene duplication and assimilation of genes from diverse sources including the host itself - some of which probably modulate important host processes. AaV also harbors a number of genes exclusive to phycodnaviruses - reinforcing the hypothesis that Phycodna- and Mimiviridae share a common ancestor.
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Affiliation(s)
| | - Gary R LeCleir
- Department of Microbiology, The University of Tennessee, TN 37996, United States
| | | | | | - Kay D Bidle
- Institute of Marine and Coastal Sciences, Rutgers, NJ 08901, United States
| | - William H Wilson
- Bigelow Lab for Ocean Sciences, Boothbay, ME 04544, United States
| | - Steven W Wilhelm
- Department of Microbiology, The University of Tennessee, TN 37996, United States.
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Bellec L, Clerissi C, Edern R, Foulon E, Simon N, Grimsley N, Desdevises Y. Cophylogenetic interactions between marine viruses and eukaryotic picophytoplankton. BMC Evol Biol 2014; 14:59. [PMID: 24669847 PMCID: PMC3983898 DOI: 10.1186/1471-2148-14-59] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2014] [Accepted: 03/20/2014] [Indexed: 01/10/2023] Open
Abstract
Background Numerous studies have investigated cospeciation (or cophylogeny) in various host-symbiont systems, and different patterns were inferred, from strict cospeciation where symbiont phylogeny mirrors host phylogeny, to complete absence of correspondence between trees. The degree of cospeciation is generally linked to the level of host specificity in the symbiont species and the opportunity they have to switch hosts. In this study, we investigated cophylogeny for the first time in a microalgae-virus association in the open sea, where symbionts are believed to be highly host-specific but have wide opportunities to switch hosts. We studied prasinovirus-Mamiellales associations using 51 different viral strains infecting 22 host strains, selected from the characterisation and experimental testing of the specificities of 313 virus strains on 26 host strains. Results All virus strains were restricted to their host genus, and most were species-specific, but some of them were able to infect different host species within a genus. Phylogenetic trees were reconstructed for viruses and their hosts, and their congruence was assessed based on these trees and the specificity data using different cophylogenetic methods, a topology-based approach, Jane, and a global congruence method, ParaFit. We found significant congruence between virus and host trees, but with a putatively complex evolutionary history. Conclusions Mechanisms other than true cospeciation, such as host-switching, might explain a part of the data. It has been observed in a previous study on the same taxa that the genomic divergence between host pairs is larger than between their viruses. It implies that if cospeciation predominates in this algae-virus system, this would support the hypothesis that prasinoviruses evolve more slowly than their microalgal hosts, whereas host switching would imply that these viruses speciated more recently than the divergence of their host genera.
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Affiliation(s)
| | | | | | | | | | | | - Yves Desdevises
- Integrative Biology of Marine Organisms, Observatoire Océanologique, Sorbonne Universités, UPMC Univ Paris 06, UMR 7232, F-66650 Banyuls-sur-Mer, France.
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