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Jian J, Wu Z, Silva-Núñez A, Li X, Zheng X, Luo B, Liu Y, Fang X, Workman CT, Larsen TO, Hansen PJ, Sonnenschein EC. Long-read genome sequencing provides novel insights into the harmful algal bloom species Prymnesium parvum. THE SCIENCE OF THE TOTAL ENVIRONMENT 2024; 908:168042. [PMID: 37898203 DOI: 10.1016/j.scitotenv.2023.168042] [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: 08/21/2023] [Revised: 10/20/2023] [Accepted: 10/20/2023] [Indexed: 10/30/2023]
Abstract
Prymnesium parvum is a toxin-producing haptophyte that causes harmful algal blooms worldwide, which are often associated with massive fish-kills and subsequent economic losses. In here, we present nuclear and plastid genome assemblies using PacBio HiFi long reads and DNBseq short reads for the two P. parvum strains UTEX 2797 and CCMP 3037, representing producers of type A prymnesins. Our results show that the P. parvum strains have a moderate haptophyte genome size of 97.56 and 107.32 Mb. The genome assemblies present one of highest contiguous assembled contig sequences to date consisting of 463 and 362 contigs with a contig N50 of 596.99 kb and 968.39 kb for strain UTEX 2797 and CCMP 3037, respectively. The assembled contigs of UTEX 2797 and CCMP 3037 were anchored to 34 scaffolds, with a scaffold N50 of 5.35 Mb and 3.61 Mb, respectively, accounting for 93.2 % and 97.9 % of the total length. Each plastid genome comprises a circular contig. A total of 20,578 and 19,426 protein-coding genes were annotated for UTEX 2797 and CCMP 3037. The expanded gene family analysis showed that starch and sucrose metabolism, sulfur metabolism, energy metabolism and ABC transporters are involved in the evolution of P. parvum. Polyketide synthase (PKS) genes responsible for the production of secondary metabolites such as prymnesins displayed different expression patterns under nutrient limitation. Overlap with repeats and horizontal gene transfer may be two contributing factors to the high number of PKS genes found in this species. The two high quality P. parvum genomes will serve as valuable resources for ecological, genetic, and toxicological studies of haptophytes that can be used to monitor and potentially manage harmful blooms of ichthyotoxic P. parvum in the future.
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Affiliation(s)
- Jianbo Jian
- Department of Biotechnology and Biomedicine, Technical University of Denmark, Lyngby, Denmark; BGI-Genomics, BGI-Shenzhen, Shenzhen, China
| | | | - Arisbe Silva-Núñez
- Department of Biotechnology and Biomedicine, Technical University of Denmark, Lyngby, Denmark; Tecnologico de Monterrey, School of Engineering and Science, Monterrey, Nuevo León, Mexico
| | - Xiaohui Li
- BGI-Genomics, BGI-Shenzhen, Shenzhen, China
| | | | - Bei Luo
- BGI-Genomics, BGI-Shenzhen, Shenzhen, China
| | - Yun Liu
- BGI-Genomics, BGI-Shenzhen, Shenzhen, China
| | | | - Christopher T Workman
- Department of Biotechnology and Biomedicine, Technical University of Denmark, Lyngby, Denmark
| | - Thomas Ostenfeld Larsen
- Department of Biotechnology and Biomedicine, Technical University of Denmark, Lyngby, Denmark
| | - Per Juel Hansen
- Marine Biological Section, University of Copenhagen, Helsingør, Denmark
| | - Eva C Sonnenschein
- Department of Biotechnology and Biomedicine, Technical University of Denmark, Lyngby, Denmark; Department of Biosciences, Swansea University, Swansea, United Kingdom.
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2
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Lobb B, Shapter A, Doxey AC, Nissimov JI. Functional Profiling and Evolutionary Analysis of a Marine Microalgal Virus Pangenome. Viruses 2023; 15:v15051116. [PMID: 37243202 DOI: 10.3390/v15051116] [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: 01/12/2023] [Accepted: 05/04/2023] [Indexed: 05/28/2023] Open
Abstract
Phycodnaviridae are large double-stranded DNA viruses, which facilitate studies of host-virus interactions and co-evolution due to their prominence in algal infection and their role in the life cycle of algal blooms. However, the genomic interpretation of these viruses is hampered by a lack of functional information, stemming from the surprising number of hypothetical genes of unknown function. It is also unclear how many of these genes are widely shared within the clade. Using one of the most extensively characterized genera, Coccolithovirus, as a case study, we combined pangenome analysis, multiple functional annotation tools, AlphaFold structural modeling, and literature analysis to compare the core and accessory pangenome and assess support for novel functional predictions. We determined that the Coccolithovirus pangenome shares 30% of its genes with all 14 strains, making up the core. Notably, 34% of its genes were found in at most three strains. Core genes were enriched in early expression based on a transcriptomic dataset of Coccolithovirus EhV-201 algal infection, were more likely to be similar to host proteins than the non-core set, and were more likely to be involved in vital functions such as replication, recombination, and repair. In addition, we generated and collated annotations for the EhV representative EhV-86 from 12 different annotation sources, building up information for 142 previously hypothetical and putative membrane proteins. AlphaFold was further able to predict structures for 204 EhV-86 proteins with a modelling accuracy of good-high. These functional clues, combined with generated AlphaFold structures, provide a foundational framework for the future characterization of this model genus (and other giant viruses) and a further look into the evolution of the Coccolithovirus proteome.
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Affiliation(s)
- Briallen Lobb
- Department of Biology, University of Waterloo, 200 University Ave. West., Waterloo, ON N2L 3G1, Canada
| | - Anson Shapter
- Department of Biology, University of Waterloo, 200 University Ave. West., Waterloo, ON N2L 3G1, Canada
| | - Andrew C Doxey
- Department of Biology, University of Waterloo, 200 University Ave. West., Waterloo, ON N2L 3G1, Canada
| | - Jozef I Nissimov
- Department of Biology, University of Waterloo, 200 University Ave. West., Waterloo, ON N2L 3G1, Canada
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3
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Nissimov JI, Vandzura R, Johns CT, Natale F, Haramaty L, Bidle KD. Dynamics of transparent exopolymer particle production and aggregation during viral infection of the coccolithophore, Emiliania huxleyi. Environ Microbiol 2018; 20:2880-2897. [PMID: 29921002 DOI: 10.1111/1462-2920.14261] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2017] [Revised: 04/25/2018] [Accepted: 04/26/2018] [Indexed: 11/30/2022]
Abstract
Emiliania huxleyi produces calcium carbonate (CaCO3 ) coccoliths and transparent exopolymer particles (TEP), sticky, acidic carbohydrates that facilitate aggregation. E. huxleyi's extensive oceanic blooms are often terminated by coccolithoviruses (EhVs) with the transport of cellular debris and associated particulate organic carbon (POC) to depth being facilitated by TEP-bound 'marine snow' aggregates. The dynamics of TEP production and particle aggregation in response to EhV infection are poorly understood. Using flow cytometry, spectrophotometry and FlowCam visualization of alcian blue (AB)-stained aggregates, we assessed TEP production and the size spectrum of aggregates for E. huxleyi possessing different degrees of calcification and cellular CaCO3 :POC mass ratios, when challenged with two EhVs (EhV207 and EhV99B1). FlowCam imaging also qualitatively assessed the relative amount of AB-stainable TEP (i.e., blue:red ratio of each particle). We show significant increases in TEP during early phase EhV207-infection (∼ 24 h) of calcifying strains and a shift towards large aggregates following EhV99B1-infection. We also observed the formation of large aggregates with low blue:red ratios, suggesting that other exopolymer substances contribute towards aggregation. Our findings show the potential for virus infection and the associated response of their hosts to impact carbon flux dynamics and provide incentive to explore these dynamics in natural populations.
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Affiliation(s)
- Jozef I Nissimov
- Department of Marine and Coastal Sciences, Rutgers University, 71 Dudley Road New Brunswick, NJ, USA
| | - Rebecca Vandzura
- Department of Marine and Coastal Sciences, Rutgers University, 71 Dudley Road New Brunswick, NJ, USA
| | - Christopher T Johns
- Department of Marine and Coastal Sciences, Rutgers University, 71 Dudley Road New Brunswick, NJ, USA
| | - Frank Natale
- Department of Marine and Coastal Sciences, Rutgers University, 71 Dudley Road New Brunswick, NJ, USA
| | - Liti Haramaty
- Department of Marine and Coastal Sciences, Rutgers University, 71 Dudley Road New Brunswick, NJ, USA
| | - Kay D Bidle
- Department of Marine and Coastal Sciences, Rutgers University, 71 Dudley Road New Brunswick, NJ, USA
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4
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Emerging Interaction Patterns in the Emiliania huxleyi-EhV System. Viruses 2017; 9:v9030061. [PMID: 28327527 PMCID: PMC5371816 DOI: 10.3390/v9030061] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2017] [Revised: 03/15/2017] [Accepted: 03/16/2017] [Indexed: 01/25/2023] Open
Abstract
Viruses are thought to be fundamental in driving microbial diversity in the oceanic planktonic realm. That role and associated emerging infection patterns remain particularly elusive for eukaryotic phytoplankton and their viruses. Here we used a vast number of strains from the model system Emiliania huxleyi/Emiliania huxleyi Virus to quantify parameters such as growth rate (µ), resistance (R), and viral production (Vp) capacities. Algal and viral abundances were monitored by flow cytometry during 72-h incubation experiments. The results pointed out higher viral production capacity in generalist EhV strains, and the virus-host infection network showed a strong co-evolution pattern between E. huxleyi and EhV populations. The existence of a trade-off between resistance and growth capacities was not confirmed.
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5
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Nissimov JI, Pagarete A, Ma F, Cody S, Dunigan DD, Kimmance SA, Allen MJ. Coccolithoviruses: A Review of Cross-Kingdom Genomic Thievery and Metabolic Thuggery. Viruses 2017; 9:v9030052. [PMID: 28335474 PMCID: PMC5371807 DOI: 10.3390/v9030052] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2017] [Revised: 03/13/2017] [Accepted: 03/14/2017] [Indexed: 11/24/2022] Open
Abstract
Coccolithoviruses (Phycodnaviridae) infect and lyse the most ubiquitous and successful coccolithophorid in modern oceans, Emiliania huxleyi. So far, the genomes of 13 of these giant lytic viruses (i.e., Emiliania huxleyi viruses—EhVs) have been sequenced, assembled, and annotated. Here, we performed an in-depth comparison of their genomes to try and contextualize the ecological and evolutionary traits of these viruses. The genomes of these EhVs have from 444 to 548 coding sequences (CDSs). Presence/absence analysis of CDSs identified putative genes with particular ecological significance, namely sialidase, phosphate permease, and sphingolipid biosynthesis. The viruses clustered into distinct clades, based on their DNA polymerase gene as well as full genome comparisons. We discuss the use of such clustering and suggest that a gene-by-gene investigation approach may be more useful when the goal is to reveal differences related to functionally important genes. A multi domain “Best BLAST hit” analysis revealed that 84% of the EhV genes have closer similarities to the domain Eukarya. However, 16% of the EhV CDSs were very similar to bacterial genes, contributing to the idea that a significant portion of the gene flow in the planktonic world inter-crosses the domains of life.
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Affiliation(s)
- Jozef I Nissimov
- Plymouth Marine Laboratory, Prospect Place, The Hoe, Plymouth PL1 3DH, UK.
- Department of Marine and Coastal Sciences, Rutgers University, New Brunswick, NJ 08901, USA.
| | - António Pagarete
- Department of Biology, University of Bergen, Bergen, 7803, Norway.
| | - Fangrui Ma
- Nebraska Center for Virology, University of Nebraska, Lincoln, NE 68583, USA.
| | - Sean Cody
- Nebraska Center for Virology, University of Nebraska, Lincoln, NE 68583, USA.
| | - David D Dunigan
- Nebraska Center for Virology, University of Nebraska, Lincoln, NE 68583, USA.
| | - Susan A Kimmance
- Plymouth Marine Laboratory, Prospect Place, The Hoe, Plymouth PL1 3DH, UK.
| | - Michael J Allen
- Plymouth Marine Laboratory, Prospect Place, The Hoe, Plymouth PL1 3DH, UK.
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6
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Kim Y, Aw TG, Teal TK, Rose JB. Metagenomic Investigation of Viral Communities in Ballast Water. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2015; 49:8396-407. [PMID: 26107908 DOI: 10.1021/acs.est.5b01633] [Citation(s) in RCA: 53] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
Ballast water is one of the most important vectors for the transport of non-native species to new aquatic environments. Due to the development of new ballast water quality standards for viruses, this study aimed to determine the taxonomic diversity and composition of viral communities (viromes) in ballast and harbor waters using metagenomics approaches. Ballast waters from different sources within the North America Great Lakes and paired harbor waters were collected around the Port of Duluth-Superior. Bioinformatics analysis of over 550 million sequences showed that a majority of the viral sequences could not be assigned to any taxa associated with reference sequences, indicating the lack of knowledge on viruses in ballast and harbor waters. However, the assigned viruses were dominated by double-stranded DNA phages, and sequences associated with potentially emerging viral pathogens of fish and shrimp were detected with low amino acid similarity in both ballast and harbor waters. Annotation-independent comparisons showed that viromes were distinct among the Great Lakes, and the Great Lakes viromes were closely related to viromes of other cold natural freshwater systems but distant from viromes of marine and human designed/managed freshwater systems. These results represent the most detailed characterization to date of viruses in ballast water, demonstrating their diversity and the potential significance of the ship-mediated spread of viruses.
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Affiliation(s)
- Yiseul Kim
- †Department of Microbiology and Molecular Genetics, Michigan State University, East Lansing, Michigan 48824, United States
| | - Tiong Gim Aw
- ‡Department of Fisheries and Wildlife, Michigan State University, East Lansing, Michigan 48824, United States
| | - Tracy K Teal
- †Department of Microbiology and Molecular Genetics, Michigan State University, East Lansing, Michigan 48824, United States
| | - Joan B Rose
- †Department of Microbiology and Molecular Genetics, Michigan State University, East Lansing, Michigan 48824, United States
- ‡Department of Fisheries and Wildlife, Michigan State University, East Lansing, Michigan 48824, United States
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7
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Nissimov JI, Napier JA, Allen MJ, Kimmance SA. Intragenus competition between coccolithoviruses: an insight on how a select few can come to dominate many. Environ Microbiol 2015; 18:133-45. [PMID: 25970076 DOI: 10.1111/1462-2920.12902] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2014] [Revised: 03/20/2015] [Accepted: 05/04/2015] [Indexed: 11/27/2022]
Abstract
Viruses are a major cause of coccolithophore bloom demise in both temperate and sub-temperate oceanic regions. Most infection studies on coccolithoviruses have been conducted with a single virus strain, and the effect of intragenus competition by closely related coccolithoviruses has been ignored. Here we conducted combined infection experiments, infecting Emiliania huxleyi CCMP 2090 with two coccolithoviruses: EhV-86 and EhV-207 both simultaneously and independently. EhV-207 displayed a shorter lytic cycle and increased production potential than EhV-86 and was remarkably superior under competitive conditions. Although the viruses displayed identical adsorption kinetics in the first 2 h post infection, EhV-207 gained a numerical advantage as early as 8 h post infection. Quantitative polymerase chain reaction (PCR) revealed that when infecting in combination, EhV-207 was not affected by the presence of EhV-86, whereas EhV-86 was quickly out-competed, and a significant reduction in free and cell-associated EhV-86 was seen as early as 2 days after the initial infection. The observation of such clear phenotypic differences between genetically distinct, yet similar, coccolithovirus strains, by flow cytometry and quantitative real-time PCR allowed tentative links to the burgeoning genomic, transcriptomic and metabolic data to be made and the factors driving their selection, in particular to the de novo coccolithovirus-encoded sphingolipid biosynthesis pathway. This work illustrates that, even within a family, not all viruses are created equally, and the potential exists for relatively small genetic changes to infer disproportionately large competitive advantages for one coccolithovirus over another, ultimately leading to a few viruses dominating the many.
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Affiliation(s)
- Jozef I Nissimov
- Plymouth Marine Laboratory, Prospect Place, The Hoe, Plymouth, PL1 3DH, UK
| | - Johnathan A Napier
- Department of Biological Chemistry, Rothamsted Research, Harpenden, Herts, AL5 2JQ, UK
| | - Michael J Allen
- Plymouth Marine Laboratory, Prospect Place, The Hoe, Plymouth, PL1 3DH, UK
| | - Susan A Kimmance
- Plymouth Marine Laboratory, Prospect Place, The Hoe, Plymouth, PL1 3DH, UK
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8
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Ji J, Zhang R, Jiao N. Complete genome sequence of Roseophage vB_DshP-R1, which infects Dinoroseobacter shibae DFL12. Stand Genomic Sci 2015; 10:6. [PMID: 26380630 PMCID: PMC4572628 DOI: 10.1186/1944-3277-10-6] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2014] [Accepted: 11/23/2014] [Indexed: 04/09/2023] Open
Abstract
The Roseophages, a group of marine viruses that uniquely infect the Roseobacter clade of bacteria, play a significant role in marine ecosystems. Here we present a complete genomic sequence of an N4 phage ‘vB_DshP-R1’, which infects Dinoroseobacter shibae DFL12, together with its structural and genomic features. vB_DshP-R1 has an ~ 75 nm diameter icosahedral structure and a complete genome of 75,028 bp. This is the first genome sequence of a lytic phage of the genus Dinoroseobacter.
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Affiliation(s)
- Jianda Ji
- State Key Laboratory of Marine Environmental Science, Institute of Marine Microbes and Ecospheres, Xiamen University, Xiamen, PR China
| | - Rui Zhang
- State Key Laboratory of Marine Environmental Science, Institute of Marine Microbes and Ecospheres, Xiamen University, Xiamen, PR China
| | - Nianzhi Jiao
- State Key Laboratory of Marine Environmental Science, Institute of Marine Microbes and Ecospheres, Xiamen University, Xiamen, PR China
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9
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Ji J, Zhang R, Jiao N. Complete genome sequence of Roseophage vB_DshP-R1, which infects Dinoroseobacter shibae DFL12. Stand Genomic Sci 2015; 9:31. [PMID: 25685262 PMCID: PMC4322955 DOI: 10.1186/1944-3277-9-31] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2014] [Accepted: 11/23/2014] [Indexed: 12/26/2022] Open
Abstract
The Roseophages, a group of marine viruses that uniquely infect the Roseobacter clade of bacteria, play a significant role in marine ecosystems. Here we present a complete genomic sequence of an N4 phage ‘vB_DshP-R1’, which infects Dinoroseobacter shibae DFL12, together with its structural and genomic features. vB_DshP-R1 has an ~ 75 nm diameter icosahedral structure and a complete genome of 75,028 bp. This is the first genome sequence of a lytic phage of the genus Dinoroseobacter.
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Affiliation(s)
- Jianda Ji
- State Key Laboratory of Marine Environmental Science, Institute of Marine Microbes and Ecospheres, Xiamen University, Xiamen, PR, China
| | - Rui Zhang
- State Key Laboratory of Marine Environmental Science, Institute of Marine Microbes and Ecospheres, Xiamen University, Xiamen, PR, China
| | - Nianzhi Jiao
- State Key Laboratory of Marine Environmental Science, Institute of Marine Microbes and Ecospheres, Xiamen University, Xiamen, PR, China
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10
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Pagarete A, Kusonmano K, Petersen K, Kimmance SA, Martínez Martínez J, Wilson WH, Hehemann JH, Allen MJ, Sandaa RA. Dip in the gene pool: metagenomic survey of natural coccolithovirus communities. Virology 2014; 466-467:129-37. [PMID: 24947907 DOI: 10.1016/j.virol.2014.05.020] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2014] [Revised: 04/23/2014] [Accepted: 05/18/2014] [Indexed: 11/30/2022]
Abstract
Despite the global oceanic distribution and recognised biogeochemical impact of coccolithoviruses (EhV), their diversity remains poorly understood. Here we employed a metagenomic approach to study the occurrence and progression of natural EhV community genomic variability. Analysis of EhV metagenomes from the early and late stages of an induced bloom led to three main discoveries. First, we observed resilient and specific genomic signatures in the EhV community associated with the Norwegian coast, which reinforce the existence of limitations to the capacity of dispersal and genomic exchange among EhV populations. Second, we identified a hyper-variable region (approximately 21kbp long) in the coccolithovirus genome. Third, we observed a clear trend for EhV relative amino-acid diversity to reduce from early to late stages of the bloom. This study validated two new methodological combinations, and proved very useful in the discovery of new genomic features associated with coccolithovirus natural communities.
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Affiliation(s)
| | | | - Kjell Petersen
- Computational Biology Unit, University of Bergen, Norway
| | | | | | - William H Wilson
- Plymouth Marine Laboratory, Plymouth, UK; Bigelow Laboratory for Ocean Sciences, East Boothbay, ME, USA
| | - Jan-Hendrik Hehemann
- Department of Civil & Environmental Engineering, Massachusetts Institute of Technology, USA
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11
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Permanent draft genomes of four new coccolithoviruses: EhV-18, EhV-145, EhV-156 and EhV-164. Mar Genomics 2014; 15:7-8. [PMID: 24631268 DOI: 10.1016/j.margen.2014.02.004] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2014] [Revised: 02/18/2014] [Accepted: 02/26/2014] [Indexed: 11/21/2022]
Abstract
Coccolithoviruses infect the marine coccolithophorid microalga Emiliania huxleyi. Here, we describe the genomes of four new coccolithoviruses isolated from UK coastal locations. Of particular interest, EhV-18 and EhV-145 encode serine palmitoyltransferase function via two distinct genes, whereas all other coccolithoviruses have SPT as a gene fusion of LCB1/LCB2 domains.
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12
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Nissimov JI, Jones M, Napier JA, Munn CB, Kimmance SA, Allen MJ. Functional inferences of environmental coccolithovirus biodiversity. Virol Sin 2013; 28:291-302. [PMID: 24006045 DOI: 10.1007/s12250-013-3362-1] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2013] [Accepted: 08/12/2013] [Indexed: 11/25/2022] Open
Abstract
The cosmopolitan calcifying alga Emiliania huxleyi is one of the most abundant bloom forming coccolithophore species in the oceans and plays an important role in global biogeochemical cycling. Coccolithoviruses are a major cause of coccolithophore bloom termination and have been studied in laboratory, mesocosm and open ocean studies. However, little is known about the dynamic interactions between the host and its viruses, and less is known about the natural diversity and role of functionally important genes within natural coccolithovirus communities. Here, we investigate the temporal and spatial distribution of coccolithoviruses by the use of molecular fingerprinting techniques PCR, DGGE and genomic sequencing. The natural biodiversity of the virus genes encoding the major capsid protein (MCP) and serine palmitoyltransferase (SPT) were analysed in samples obtained from the Atlantic Meridional Transect (AMT), the North Sea and the L4 site in the Western Channel Observatory. We discovered nine new coccolithovirus genotypes across the AMT and L4 site, with the majority of MCP sequences observed at the deep chlorophyll maximum layer of the sampled sites on the transect. We also found four new SPT gene variations in the North Sea and at L4. Their translated fragments and the full protein sequence of SPT from laboratory strains EhV-86 and EhV-99B1 were modelled and revealed that the theoretical fold differs among strains. Variation identified in the structural distance between the two domains of the SPT protein may have an impact on the catalytic capabilities of its active site. In summary, the combined use of 'standard' markers (i.e. MCP), in combination with metabolically relevant markers (i.e. SPT) are useful in the study of the phylogeny and functional biodiversity of coccolithoviruses, and can provide an interesting intracellular insight into the evolution of these viruses and their ability to infect and replicate within their algal hosts.
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Affiliation(s)
- Jozef I Nissimov
- Plymouth Marine Laboratory, Prospect Place, Plymouth, PL1 3DH, UK
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13
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Draft genome sequence of four coccolithoviruses: Emiliania huxleyi virus EhV-88, EhV-201, EhV-207, and EhV-208. J Virol 2012; 86:2896-7. [PMID: 22328700 DOI: 10.1128/jvi.07046-11] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The Coccolithoviridae are a group of viruses which infect the marine coccolithophorid microalga Emiliania huxleyi. The Emiliania huxleyi viruses (known as EhVs) described herein have 160- to 180-nm diameter icosahedral structures, have genomes of approximately 400 kbp, and consist of more than 450 predicted coding sequences (CDSs). Here, we describe the genomic features of four newly sequenced coccolithoviruses (EhV-88, EhV-201, EhV-207, and EhV-208) together with their draft genome sequences and their annotations, highlighting the homology and heterogeneity of these genomes to the EhV-86 model reference genome.
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14
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Abstract
Emiliania huxleyi virus 202 (EhV-202) is a member of the Coccolithoviridae, a group of viruses that infect the marine coccolithophorid Emiliania huxleyi. EhV-202 has a 160- to 180-nm-diameter icosahedral structure and a genome of approximately 407 kbp, consisting of 485 coding sequences (CDSs). Here we describe the genomic features of EhV-202, together with a draft genome sequence and its annotation, highlighting the homology and heterogeneity of this genome in comparison with the EhV-86 reference genome.
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15
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16
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Affiliation(s)
- George M Garrity
- Department of Microbiology and Molecular Genetics, Michigan State University
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