1
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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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2
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Joffe N, Kuhlisch C, Schleyer G, Ahlers NS, Shemi A, Vardi A. Cell-to-cell heterogeneity drives host-virus coexistence in a bloom-forming alga. THE ISME JOURNAL 2024; 18:wrae038. [PMID: 38452203 PMCID: PMC10980834 DOI: 10.1093/ismejo/wrae038] [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: 11/30/2023] [Revised: 01/25/2024] [Accepted: 03/04/2024] [Indexed: 03/09/2024]
Abstract
Algal blooms drive global biogeochemical cycles of key nutrients and serve as hotspots for biological interactions in the ocean. The massive blooms of the cosmopolitan coccolithophore Emiliania huxleyi are often infected by the lytic E. huxleyi virus, which is a major mortality agent triggering bloom demise. This multi-annual "boom and bust" pattern of E. huxleyi blooms suggests that coexistence is essential for these host-virus dynamics. To investigate host-virus coexistence, we developed a new model system from an E. huxleyi culture that recovered from viral infection. The recovered population coexists with the virus, as host cells continue to divide in parallel to viral production. By applying single-molecule fluorescence in situ hybridization (smFISH) to quantify the fraction of infected cells, and assessing infection-specific lipid biomarkers, we identified a small subpopulation of cells that were infected and produced new virions, whereas most of the host population could resist infection. To further assess population heterogeneity, we generated clonal strain collections using single-cell sorting and subsequently phenotyped their susceptibility to E. huxleyi virus infection. This unraveled substantial cell-to-cell heterogeneity across a continuum of susceptibility to resistance, highlighting that infection outcome may vary depending on the individual cell. These results add a new dimension to our understanding of the complexity of host-virus interactions that are commonly assessed in bulk and described by binary definitions of resistance or susceptibility. We propose that phenotypic heterogeneity drives the host-virus coexistence and demonstrate how the coexistence with a lytic virus provides an ecological advantage for the host by killing competing strains.
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Affiliation(s)
- Nir Joffe
- Department of Plant and Environmental Sciences, Weizmann Institute of Science, 7610001 Rehovot, Israel
| | - Constanze Kuhlisch
- Department of Plant and Environmental Sciences, Weizmann Institute of Science, 7610001 Rehovot, Israel
| | - Guy Schleyer
- Department of Plant and Environmental Sciences, Weizmann Institute of Science, 7610001 Rehovot, Israel
- Department of Biomolecular Chemistry, Leibniz Institute for Natural Product Research and Infection Biology—Hans Knöll Institute, 07745 Jena, Germany
| | - Nadia S Ahlers
- Department of Plant and Environmental Sciences, Weizmann Institute of Science, 7610001 Rehovot, Israel
| | - Adva Shemi
- Department of Plant and Environmental Sciences, Weizmann Institute of Science, 7610001 Rehovot, Israel
| | - Assaf Vardi
- Department of Plant and Environmental Sciences, Weizmann Institute of Science, 7610001 Rehovot, Israel
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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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Hongo Y, Kimura K, Takaki Y, Yoshida Y, Baba S, Kobayashi G, Nagasaki K, Hano T, Tomaru Y. The genome of the diatom Chaetoceros tenuissimus carries an ancient integrated fragment of an extant virus. Sci Rep 2021; 11:22877. [PMID: 34819553 PMCID: PMC8613185 DOI: 10.1038/s41598-021-00565-3] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2021] [Accepted: 10/11/2021] [Indexed: 11/09/2022] Open
Abstract
Diatoms are one of the most prominent oceanic primary producers and are now recognized to be distributed throughout the world. They maintain their population despite predators, infections, and unfavourable environmental conditions. One of the smallest diatoms, Chaetoceros tenuissimus, can coexist with infectious viruses during blooms. To further understand this relationship, we sequenced the C. tenuissimus strain NIES-3715 genome. A gene fragment of a replication-associated gene from the infectious ssDNA virus (designated endogenous virus-like fragment, EVLF) was found to be integrated into each 41 Mb of haploid assembly. In addition, the EVLF was transcriptionally active and conserved in nine other C. tenuissimus strains from different geographical areas, although the primary structures of their proteins varied. The phylogenetic tree further suggested that the EVLF was acquired by the ancestor of C. tenuissimus. Additionally, retrotransposon genes possessing a reverse transcriptase function were more abundant in C. tenuissimus than in Thalassiosira pseudonana and Phaeodactylum tricornutum. Moreover, a target site duplication, a hallmark for long interspersed nuclear element retrotransposons, flanked the EVLF. Therefore, the EVLF was likely integrated by a retrotransposon during viral infection. The present study provides further insights into the diatom-virus evolutionary relationship.
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Affiliation(s)
- Yuki Hongo
- Fisheries Resources Institute, Japan Fisheries Research and Education Agency, 2-12-4 Fukuura, Kanazawa, Yokohama, Kanagawa, 236-8648, Japan.
| | - Kei Kimura
- Faculty of Agriculture, Saga University, 1 Honjo-machi, Saga, 840-8502, Japan
| | - Yoshihiro Takaki
- Super-Cutting-Edge Grand and Advanced Research Program, Japan Agency for Marine-Earth Science and Technology, 2-15 Natsushima-cho, Yokosuka, Kanagawa, 237-0061, Japan
| | - Yukari Yoshida
- Super-Cutting-Edge Grand and Advanced Research Program, Japan Agency for Marine-Earth Science and Technology, 2-15 Natsushima-cho, Yokosuka, Kanagawa, 237-0061, Japan
| | - Shuichiro Baba
- United Graduate School of Agricultural Sciences, Kagoshima University, 1-21-24 Korimoto, Kagoshima, 890-0065, Japan
| | - Genta Kobayashi
- Faculty of Agriculture, Saga University, 1 Honjo-machi, Saga, 840-8502, Japan
| | - Keizo Nagasaki
- Faculty of Science and Technology, Kochi University, 200 Otsu, Monobe, Nankoku, Kochi, 783-8502, Japan
| | - Takeshi Hano
- Fisheries Technology Institute, Japan Fisheries Research and Education Agency, 2-17-5 Maruishi, Hatsukaichi, Hiroshima, 739-0452, Japan
| | - Yuji Tomaru
- Fisheries Technology Institute, Japan Fisheries Research and Education Agency, 2-17-5 Maruishi, Hatsukaichi, Hiroshima, 739-0452, Japan.
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5
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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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6
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Tomaru Y, Yamaguchi H, Miki T. Growth Rate-dependent Cell Death of Diatoms due to Viral Infection and Their Subsequent Coexistence in a Semi-continuous Culture System. Microbes Environ 2021; 36. [PMID: 33390375 PMCID: PMC7966941 DOI: 10.1264/jsme2.me20116] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
Abstract
Viral infections are a major factor in diatom cell death. However, the effects of viruses on diatom dynamics remain unclear. Based on laboratory studies, it is hypothesized that virus-induced diatom mortality is dependent on the diatom growth rate. The present study aimed to elucidate the relationship between the diatom growth rate and virus-induced mortality using model systems of the marine planktonic diatom, Chaetoceros tenuissimus and its infectious viruses. We also examined the fate of diatom populations in a semi-continuous dilution culture system, in which host growth rates were controlled at 0.69, 2.08, and 3.47 day–1. Diatom populations gradually decreased following the viral inoculation of each culture system, and virus-induced mortality inversely correlated with the diatom growth rate. Furthermore, the viral burst size was slightly higher in lower growth rate cultures. These results suggested that the host physiological status related to the growth rate affected viral infection and proliferation. Diatom populations were not completely lysed or washed out in any of the dilution systems; they showed steady growth in the presence of infectious viruses. This may be partially explained by defective interference particles from viruses and cell debris. The present results indicate that diatoms in dilution environments maintain their populations, even under viral pressure. Moreover, diatom populations with a low growth rate may partially sustain higher growth populations through nutrient recycling following virus-induced cell death. The results of the present study provide insights into diatom dynamics in natural environments in the presence of infectious viruses.
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Affiliation(s)
- Yuji Tomaru
- Hatsukaichi Field Station, Fisheries Technology Institute, Japan Fisheries Research and Education Agency, National Research and Development Agency
| | | | - Takeshi Miki
- Ecology and Environmental Engineering, Faculty of Advanced Science and Technology, Ryukoku University
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7
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Castillo YM, Forn I, Yau S, Morán XAG, Alonso-Sáez L, Arandia-Gorostidi N, Vaqué D, Sebastián M. Seasonal dynamics of natural Ostreococcus viral infection at the single cell level using VirusFISH. Environ Microbiol 2021; 23:3009-3019. [PMID: 33817943 DOI: 10.1111/1462-2920.15504] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2020] [Accepted: 04/03/2021] [Indexed: 11/28/2022]
Abstract
Ostreococcus is a cosmopolitan marine genus of phytoplankton found in mesotrophic and oligotrophic waters, and the smallest free-living eukaryotes known to date, with a cell diameter close to 1 μm. Ostreococcus has been extensively studied as a model system to investigate viral-host dynamics in culture, yet the impact of viruses in naturally occurring populations is largely unknown. Here, we used Virus Fluorescence in situ Hybridization (VirusFISH) to visualize and quantify viral-host dynamics in natural populations of Ostreococcus during a seasonal cycle in the central Cantabrian Sea (Southern Bay of Biscay). Ostreococcus were predominantly found during summer and autumn at surface and 50 m depth, in coastal, mid-shelf and shelf waters, representing up to 21% of the picoeukaryotic communities. Viral infection was only detected in surface waters, and its impact was variable but highest from May to July and November to December, when up to half of the population was infected. Metatranscriptomic data available from the mid-shelf station unveiled that the Ostreococcus population was dominated by the species O. lucimarinus. This work represents a proof of concept that the VirusFISH technique can be used to quantify the impact of viruses on targeted populations of key microbes from complex natural communities.
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Affiliation(s)
- Yaiza M Castillo
- Department of Marine Biology and Oceanography, Institute of Marine Sciences (CSIC), Barcelona, Spain
| | - Irene Forn
- Department of Marine Biology and Oceanography, Institute of Marine Sciences (CSIC), Barcelona, Spain
| | - Sheree Yau
- Department of Marine Biology and Oceanography, Institute of Marine Sciences (CSIC), Barcelona, Spain
| | - Xosé Anxelu G Morán
- Red Sea Research Center, King Abdullah University of Science and Technology (KAUST), Thuwal, Saudi Arabia
| | - Laura Alonso-Sáez
- Centro Oceanográfico de Gijón/Xixón, IEO, Gijón/Xixón, Spain.,AZTI Marine Research, Basque Research and Technology Alliance (BRTA), Txatxarramendi ugartea z/g, Sukarrieta, Spain
| | - Néstor Arandia-Gorostidi
- Centro Oceanográfico de Gijón/Xixón, IEO, Gijón/Xixón, Spain.,Department of Earth System Science, Stanford University, Stanford, CA, USA
| | - Dolors Vaqué
- Department of Marine Biology and Oceanography, Institute of Marine Sciences (CSIC), Barcelona, Spain
| | - Marta Sebastián
- Department of Marine Biology and Oceanography, Institute of Marine Sciences (CSIC), Barcelona, Spain.,Institute of Oceanography and Global Change (IOCAG), University of Las Palmas de Gran Canaria (ULPGC), Telde, Spain
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8
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Demory D, Weitz JS, Baudoux AC, Touzeau S, Simon N, Rabouille S, Sciandra A, Bernard O. A thermal trade-off between viral production and degradation drives virus-phytoplankton population dynamics. Ecol Lett 2021; 24:1133-1144. [PMID: 33877734 DOI: 10.1111/ele.13722] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2020] [Revised: 09/24/2020] [Accepted: 02/11/2021] [Indexed: 12/13/2022]
Abstract
Marine viruses interact with microbial hosts in dynamic environments shaped by variation in abiotic factors, including temperature. However, the impacts of temperature on viral infection of phytoplankton are not well understood. Here we coupled mathematical modelling with experiments to explore the effect of temperature on virus-phytoplankton interactions. Our model shows the negative consequences of high temperatures on infection and suggests a temperature-dependent threshold between viral production and degradation. Modelling long-term dynamics in environments with different average temperatures revealed the potential for long-term host-virus coexistence, epidemic free or habitat loss states. We generalised our model to variation in global sea surface temperatures corresponding to present and future seas and show that climate change may differentially influence virus-host dynamics depending on the virus-host pair. Temperature-dependent changes in the infectivity of virus particles may lead to shifts in virus-host habitats in warmer oceans, analogous to projected changes in the habitats of macro-, microorganisms and pathogens.
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Affiliation(s)
- David Demory
- School of Biological Sciences, Georgia Institute of Technology, Atlanta, GA, USA
| | - Joshua S Weitz
- School of Biological Sciences, Georgia Institute of Technology, Atlanta, GA, USA.,School of Physics, Georgia Institute of Technology, Atlanta, GA, USA
| | - Anne-Claire Baudoux
- Sorbonne Université, CNRS, UMR 7144 - Ecology of Marine Plankton, Station Biologique de Roscoff, Roscoff, 29860, France
| | - Suzanne Touzeau
- Université Côte d'Azur, INRIA, INRAE, CNRS, Sorbonne Université, BIOCORE, Sophia Antipolis, 06902, France.,Université Côte d'Azur, INRAE, CNRS, ISA, Sophia Antipolis, France
| | - Natalie Simon
- Sorbonne Université, CNRS, UMR 7144 - Ecology of Marine Plankton, Station Biologique de Roscoff, Roscoff, 29860, France
| | - Sophie Rabouille
- Sorbonne Université, CNRS, UMR 7621 - Laboratoire d'Océanographie Microbienne, Banyuls-sur-Mer, 66650, France
| | - Antoine Sciandra
- Sorbonne Université, CNRS, UMR 7093 - Laboratoire d'Océanographie de Villefranche, Villefranche-sur-Mer, 06230, France
| | - Olivier Bernard
- Université Côte d'Azur, INRIA, INRAE, CNRS, Sorbonne Université, BIOCORE, Sophia Antipolis, 06902, France
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9
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Chaudhari HV, Inamdar MM, Kondabagil K. Scaling relation between genome length and particle size of viruses provides insights into viral life history. iScience 2021; 24:102452. [PMID: 34113814 PMCID: PMC8169800 DOI: 10.1016/j.isci.2021.102452] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2021] [Revised: 03/23/2021] [Accepted: 04/15/2021] [Indexed: 12/12/2022] Open
Abstract
In terms of genome and particle sizes, viruses exhibit great diversity. With the discovery of several nucleocytoplasmic large DNA viruses (NCLDVs) and jumbo phages, the relationship between particle and genome sizes has emerged as an important criterion for understanding virus evolution. We use allometric scaling of capsid volume with the genome length of different groups of viruses to shed light on its relationship with virus life history. The allometric exponents for icosahedral dsDNA bacteriophages and NCDLVs were found to be 1 and 2, respectively, indicating that with increasing capsid size DNA packaging density remains the same in bacteriophages but decreases for NCLDVs. We argue that the exponents are largely shaped by their entry mechanism and capsid mechanical stability. We further show that these allometric size parameters are also intricately linked to the relative energy costs of translation and replication in viruses and can have further implications on viral life history. Capsid and genome size allometric exponent gives insights into viral life history The allometric exponent of NCLDVs is almost twice that of bacteriophages The exponent is largely shaped by the viral entry mechanism and capsid stability The relaxed genome size constraint allows large viruses to evolve greater autonomy
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Affiliation(s)
- Harshali V Chaudhari
- Department of Biosciences and Bioengineering, Indian Institute of Technology Bombay, Powai, Mumbai 400076, India
| | - Mandar M Inamdar
- Department of Civil Engineering, Indian Institute of Technology Bombay, Powai, Mumbai 400076, India
| | - Kiran Kondabagil
- Department of Biosciences and Bioengineering, Indian Institute of Technology Bombay, Powai, Mumbai 400076, India
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10
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Edwards KF, Steward GF, Schvarcz CR. Making sense of virus size and the tradeoffs shaping viral fitness. Ecol Lett 2020; 24:363-373. [PMID: 33146939 DOI: 10.1111/ele.13630] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2020] [Revised: 06/26/2020] [Accepted: 09/27/2020] [Indexed: 12/18/2022]
Abstract
Viruses span an impressive size range, with genome length varying a thousandfold and virion volume nearly a millionfold. For cellular organisms the scaling of traits with size is a pervasive influence on ecological processes, but whether size plays a central role in viral ecology is unknown. Here, we focus on viruses of aquatic unicellular organisms, which exhibit the greatest known range of virus size. We outline hypotheses within a quantitative framework, and analyse data where available, to consider how size affects the primary components of viral fitness. We argue that larger viruses have fewer offspring per infection and slower contact rates with host cells, but a larger genome tends to increase infection efficiency, broaden host range, and potentially increase attachment success and decrease decay rate. These countervailing selective pressures may explain why a breadth of sizes exist and even coexist when infecting the same host populations. Oligotrophic ecosystems may be enriched in "giant" viruses, because environments with resource-limited phagotrophs at low concentrations may select for broader host range, better control of host metabolism, lower decay rate and a physical size that mimics bacterial prey. Finally, we describe where further research is needed to understand the ecology and evolution of viral size diversity.
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Affiliation(s)
- Kyle F Edwards
- Department of Oceanography, University of Hawai'i at Mānoa, Honolulu, HI, USA
| | - Grieg F Steward
- Department of Oceanography, University of Hawai'i at Mānoa, Honolulu, HI, USA
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11
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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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12
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Zimmerman AE, Howard-Varona C, Needham DM, John SG, Worden AZ, Sullivan MB, Waldbauer JR, Coleman ML. Metabolic and biogeochemical consequences of viral infection in aquatic ecosystems. Nat Rev Microbiol 2019; 18:21-34. [PMID: 31690825 DOI: 10.1038/s41579-019-0270-x] [Citation(s) in RCA: 158] [Impact Index Per Article: 31.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/09/2019] [Indexed: 12/23/2022]
Abstract
Ecosystems are controlled by 'bottom-up' (resources) and 'top-down' (predation) forces. Viral infection is now recognized as a ubiquitous top-down control of microbial growth across ecosystems but, at the same time, cell death by viral predation influences, and is influenced by, resource availability. In this Review, we discuss recent advances in understanding the biogeochemical impact of viruses, focusing on how metabolic reprogramming of host cells during lytic viral infection alters the flow of energy and nutrients in aquatic ecosystems. Our synthesis revealed several emerging themes. First, viral infection transforms host metabolism, in part through virus-encoded metabolic genes; the functions performed by these genes appear to alleviate energetic and biosynthetic bottlenecks to viral production. Second, viral infection depends on the physiological state of the host cell and on environmental conditions, which are challenging to replicate in the laboratory. Last, metabolic reprogramming of infected cells and viral lysis alter nutrient cycling and carbon export in the oceans, although the net impacts remain uncertain. This Review highlights the need for understanding viral infection dynamics in realistic physiological and environmental contexts to better predict their biogeochemical consequences.
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Affiliation(s)
- Amy E Zimmerman
- Department of the Geophysical Sciences, University of Chicago, Chicago, IL, USA
| | | | - David M Needham
- Monterey Bay Aquarium Research Institute, Moss Landing, CA, USA
| | - Seth G John
- Department of Earth Science, University of Southern California, Los Angeles, CA, USA
| | - Alexandra Z Worden
- Monterey Bay Aquarium Research Institute, Moss Landing, CA, USA.,Ocean EcoSystems Biology Unit, GEOMAR Helmholtz Centre for Ocean Research Kiel, Kiel, Germany
| | - Matthew B Sullivan
- Department of Microbiology, Ohio State University, Columbus, OH, USA.,Department of Civil, Environmental and Geodetic Engineering, Ohio State University, Columbus, OH, USA
| | - Jacob R Waldbauer
- Department of the Geophysical Sciences, University of Chicago, Chicago, IL, USA
| | - Maureen L Coleman
- Department of the Geophysical Sciences, University of Chicago, Chicago, IL, USA.
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13
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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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14
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Horas EL, Theodosiou L, Becks L. Why Are Algal Viruses Not Always Successful? Viruses 2018; 10:v10090474. [PMID: 30189587 PMCID: PMC6165140 DOI: 10.3390/v10090474] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2018] [Revised: 08/31/2018] [Accepted: 09/02/2018] [Indexed: 12/14/2022] Open
Abstract
Algal viruses are considered to be key players in structuring microbial communities and biogeochemical cycles due to their abundance and diversity within aquatic systems. Their high reproduction rates and short generation times make them extremely successful, often with immediate and strong effects for their hosts and thus in biological and abiotic environments. There are, however, conditions that decrease their reproduction rates and make them unsuccessful with no or little immediate effects. Here, we review the factors that lower viral success and divide them into intrinsic—when they are related to the life cycle traits of the virus—and extrinsic factors—when they are external to the virus and related to their environment. Identifying whether and how algal viruses adapt to disadvantageous conditions will allow us to better understand their role in aquatic systems. We propose important research directions such as experimental evolution or the resurrection of extinct viruses to disentangle the conditions that make them unsuccessful and the effects these have on their surroundings.
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Affiliation(s)
- Elena L Horas
- Community Dynamics Group, Max-Planck for Evolutionary Biology, 24306 Plön, Germany.
- Limnology-Aquatic Ecology and Evolution, Limnological Institute, University of Konstanz, 78464 Konstanz, Germany.
| | - Loukas Theodosiou
- Community Dynamics Group, Max-Planck for Evolutionary Biology, 24306 Plön, Germany.
- Department of Microbial Population Biology, Max-Planck for Evolutionary Biology, 24306 Plön, Germany.
| | - Lutz Becks
- Community Dynamics Group, Max-Planck for Evolutionary Biology, 24306 Plön, Germany.
- Limnology-Aquatic Ecology and Evolution, Limnological Institute, University of Konstanz, 78464 Konstanz, Germany.
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15
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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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16
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Abstract
Viruses are integral to ecological and evolutionary processes, but we have a poor understanding of what drives variation in key traits across diverse viruses. For lytic viruses, burst size, latent period, and genome size are primary characteristics controlling host-virus dynamics. Here we synthesize data on these traits for 75 strains of phytoplankton viruses, which play an important role in global biogeochemistry. We find that primary traits of the host (genome size, growth rate) explain 40%-50% of variation in burst size and latent period. Specifically, burst size and latent period both exhibit saturating relationships versus the host∶virus genome size ratio, with both traits increasing at low genome size ratios while showing no relationship at high size ratios. In addition, latent period declines as host growth rate increases. We analyze a model of latent period evolution to explore mechanisms that could cause these patterns. The model predicts that burst size may often be set by the host genomic resources available for viral construction, while latent period evolves to permit this maximal burst size, modulated by host metabolic rate. These results suggest that general mechanisms may underlie the evolution of diverse viruses. Future extensions of this work could help explain viral regulation of host populations, viral influence on community structure and diversity, and viral roles in biogeochemical cycles.
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17
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Steele DJ, Kimmance SA, Franklin DJ, Airs RL. Occurrence of chlorophyll allomers during virus-induced mortality and population decline in the ubiquitous picoeukaryoteOstreococcus tauri. Environ Microbiol 2017; 20:588-601. [DOI: 10.1111/1462-2920.13980] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2015] [Accepted: 10/31/2017] [Indexed: 11/29/2022]
Affiliation(s)
- Deborah J. Steele
- Plymouth Marine Laboratory, Prospect Place; Plymouth UK
- Faculty of Science and Technology; Bournemouth University; Poole UK
| | | | | | - Ruth L. Airs
- Plymouth Marine Laboratory, Prospect Place; Plymouth UK
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18
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Frada MJ, Rosenwasser S, Ben-Dor S, Shemi A, Sabanay H, Vardi A. Morphological switch to a resistant subpopulation in response to viral infection in the bloom-forming coccolithophore Emiliania huxleyi. PLoS Pathog 2017; 13:e1006775. [PMID: 29244854 PMCID: PMC5756048 DOI: 10.1371/journal.ppat.1006775] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2017] [Revised: 01/05/2018] [Accepted: 11/27/2017] [Indexed: 11/18/2022] Open
Abstract
Recognizing the life cycle of an organism is key to understanding its biology and ecological impact. Emiliania huxleyi is a cosmopolitan marine microalga, which displays a poorly understood biphasic sexual life cycle comprised of a calcified diploid phase and a morphologically distinct biflagellate haploid phase. Diploid cells (2N) form large-scale blooms in the oceans, which are routinely terminated by specific lytic viruses (EhV). In contrast, haploid cells (1N) are resistant to EhV. Further evidence indicates that 1N cells may be produced during viral infection. A shift in morphology, driven by meiosis, could therefore constitute a mechanism for E. huxleyi cells to escape from EhV during blooms. This process has been metaphorically coined the 'Cheshire Cat' (CC) strategy. We tested this model in two E. huxleyi strains using a detailed assessment of morphological and ploidy-level variations as well as expression of gene markers for meiosis and the flagellate phenotype. We showed that following the CC model, production of resistant cells was triggered during infection. This led to the rise of a new subpopulation of cells in the two strains that morphologically resembled haploid cells and were resistant to EhV. However, ploidy-level analyses indicated that the new resistant cells were diploid or aneuploid. Thus, the CC strategy in E. huxleyi appears to be a life-phase switch mechanism involving morphological remodeling that is decoupled from meiosis. Our results highlight the adaptive significance of morphological plasticity mediating complex host-virus interactions in marine phytoplankton.
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Affiliation(s)
- Miguel José Frada
- Department of Plant and Environmental Sciences, Weizmann Institute of Science, Rehovot, Israel
| | - Shilo Rosenwasser
- Department of Plant and Environmental Sciences, Weizmann Institute of Science, Rehovot, Israel
| | - Shifra Ben-Dor
- Bioinformatics and Biological Computing Unit–Department of Biological Services, Weizmann Institute of Science, Rehovot, Israel
| | - Adva Shemi
- Department of Plant and Environmental Sciences, Weizmann Institute of Science, Rehovot, Israel
| | - Helena Sabanay
- Department of Chemical Research Support, Weizmann Institute of Science, Rehovot, Israel
| | - Assaf Vardi
- Department of Plant and Environmental Sciences, Weizmann Institute of Science, Rehovot, Israel
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19
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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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20
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Blanc-Mathieu R, Krasovec M, Hebrard M, Yau S, Desgranges E, Martin J, Schackwitz W, Kuo A, Salin G, Donnadieu C, Desdevises Y, Sanchez-Ferandin S, Moreau H, Rivals E, Grigoriev IV, Grimsley N, Eyre-Walker A, Piganeau G. Population genomics of picophytoplankton unveils novel chromosome hypervariability. SCIENCE ADVANCES 2017; 3:e1700239. [PMID: 28695208 PMCID: PMC5498103 DOI: 10.1126/sciadv.1700239] [Citation(s) in RCA: 50] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/23/2017] [Accepted: 05/25/2017] [Indexed: 05/18/2023]
Abstract
Tiny photosynthetic microorganisms that form the picoplankton (between 0.3 and 3 μm in diameter) are at the base of the food web in many marine ecosystems, and their adaptability to environmental change hinges on standing genetic variation. Although the genomic and phenotypic diversity of the bacterial component of the oceans has been intensively studied, little is known about the genomic and phenotypic diversity within each of the diverse eukaryotic species present. We report the level of genomic diversity in a natural population of Ostreococcus tauri (Chlorophyta, Mamiellophyceae), the smallest photosynthetic eukaryote. Contrary to the expectations of clonal evolution or cryptic species, the spectrum of genomic polymorphism observed suggests a large panmictic population (an effective population size of 1.2 × 107) with pervasive evidence of sexual reproduction. De novo assemblies of low-coverage chromosomes reveal two large candidate mating-type loci with suppressed recombination, whose origin may pre-date the speciation events in the class Mamiellophyceae. This high genetic diversity is associated with large phenotypic differences between strains. Strikingly, resistance of isolates to large double-stranded DNA viruses, which abound in their natural environment, is positively correlated with the size of a single hypervariable chromosome, which contains 44 to 156 kb of strain-specific sequences. Our findings highlight the role of viruses in shaping genome diversity in marine picoeukaryotes.
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Affiliation(s)
- Romain Blanc-Mathieu
- Bioinformatics Center, Institute for Chemical Research, Kyoto University, Uji, Kyoto 611-0011, Japan
- CNRS, Biologie Intégrative des Organismes Marins (BIOM), Observatoire Océanologique, F-66650 Banyuls-sur-Mer, France
| | - Marc Krasovec
- CNRS, Biologie Intégrative des Organismes Marins (BIOM), Observatoire Océanologique, F-66650 Banyuls-sur-Mer, France
- Sorbonne Universités, Université Pierre et Marie Curie, UMR7232, BIOM, Observatoire Océanologique, F-66650 Banyuls-sur-Mer, France
| | - Maxime Hebrard
- Laboratoire d’Informatique, de Robotique et de Microélectronique de Montpellier, CNRS, and Université de Montpellier, 161 rue Ada, 34095 Montpellier Cedex 5, France
- Institut de Biologie Computationnelle, CNRS, and Université de Montpellier, 860 rue Saint Priest, 34095 Montpellier Cedex 5, France
| | - Sheree Yau
- CNRS, Biologie Intégrative des Organismes Marins (BIOM), Observatoire Océanologique, F-66650 Banyuls-sur-Mer, France
- Sorbonne Universités, Université Pierre et Marie Curie, UMR7232, BIOM, Observatoire Océanologique, F-66650 Banyuls-sur-Mer, France
| | - Elodie Desgranges
- CNRS, Biologie Intégrative des Organismes Marins (BIOM), Observatoire Océanologique, F-66650 Banyuls-sur-Mer, France
- Sorbonne Universités, Université Pierre et Marie Curie, UMR7232, BIOM, Observatoire Océanologique, F-66650 Banyuls-sur-Mer, France
| | - Joel Martin
- U.S. Department of Energy Joint Genome Institute, Walnut Creek, CA 94598, USA
| | - Wendy Schackwitz
- U.S. Department of Energy Joint Genome Institute, Walnut Creek, CA 94598, USA
| | - Alan Kuo
- U.S. Department of Energy Joint Genome Institute, Walnut Creek, CA 94598, USA
| | - Gerald Salin
- INRA, plateforme Génome et Transcriptome (GeT-PlaGe), GenoToul, Castanet-Tolosan, France
| | - Cecile Donnadieu
- INRA, plateforme Génome et Transcriptome (GeT-PlaGe), GenoToul, Castanet-Tolosan, France
| | - Yves Desdevises
- CNRS, Biologie Intégrative des Organismes Marins (BIOM), Observatoire Océanologique, F-66650 Banyuls-sur-Mer, France
- Sorbonne Universités, Université Pierre et Marie Curie, UMR7232, BIOM, Observatoire Océanologique, F-66650 Banyuls-sur-Mer, France
| | - Sophie Sanchez-Ferandin
- CNRS, Biologie Intégrative des Organismes Marins (BIOM), Observatoire Océanologique, F-66650 Banyuls-sur-Mer, France
- Sorbonne Universités, Université Pierre et Marie Curie, UMR7232, BIOM, Observatoire Océanologique, F-66650 Banyuls-sur-Mer, France
| | - Hervé Moreau
- CNRS, Biologie Intégrative des Organismes Marins (BIOM), Observatoire Océanologique, F-66650 Banyuls-sur-Mer, France
- Sorbonne Universités, Université Pierre et Marie Curie, UMR7232, BIOM, Observatoire Océanologique, F-66650 Banyuls-sur-Mer, France
| | - Eric Rivals
- Laboratoire d’Informatique, de Robotique et de Microélectronique de Montpellier, CNRS, and Université de Montpellier, 161 rue Ada, 34095 Montpellier Cedex 5, France
- Institut de Biologie Computationnelle, CNRS, and Université de Montpellier, 860 rue Saint Priest, 34095 Montpellier Cedex 5, France
| | - Igor V. Grigoriev
- U.S. Department of Energy Joint Genome Institute, Walnut Creek, CA 94598, USA
- Department of Plant and Microbial Biology, University of California, Berkeley, 111 Koshland Hall, Berkeley, CA 94720, USA
| | - Nigel Grimsley
- CNRS, Biologie Intégrative des Organismes Marins (BIOM), Observatoire Océanologique, F-66650 Banyuls-sur-Mer, France
- Sorbonne Universités, Université Pierre et Marie Curie, UMR7232, BIOM, Observatoire Océanologique, F-66650 Banyuls-sur-Mer, France
| | - Adam Eyre-Walker
- School of Life Sciences, University of Sussex, Brighton BN1 9QG, UK
| | - Gwenael Piganeau
- CNRS, Biologie Intégrative des Organismes Marins (BIOM), Observatoire Océanologique, F-66650 Banyuls-sur-Mer, France
- Sorbonne Universités, Université Pierre et Marie Curie, UMR7232, BIOM, Observatoire Océanologique, F-66650 Banyuls-sur-Mer, France
- School of Life Sciences, University of Sussex, Brighton BN1 9QG, UK
- Corresponding author.
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21
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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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22
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Seasonal Dynamics of Haptophytes and dsDNA Algal Viruses Suggest Complex Virus-Host Relationship. Viruses 2017; 9:v9040084. [PMID: 28425942 PMCID: PMC5408690 DOI: 10.3390/v9040084] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2017] [Revised: 04/06/2017] [Accepted: 04/13/2017] [Indexed: 01/06/2023] Open
Abstract
Viruses influence the ecology and diversity of phytoplankton in the ocean. Most studies of phytoplankton host-virus interactions have focused on bloom-forming species like Emiliania huxleyi or Phaeocystis spp. The role of viruses infecting phytoplankton that do not form conspicuous blooms have received less attention. Here we explore the dynamics of phytoplankton and algal viruses over several sequential seasons, with a focus on the ubiquitous and diverse phytoplankton division Haptophyta, and their double-stranded DNA viruses, potentially with the capacity to infect the haptophytes. Viral and phytoplankton abundance and diversity showed recurrent seasonal changes, mainly explained by hydrographic conditions. By 454 tag-sequencing we revealed 93 unique haptophyte operational taxonomic units (OTUs), with seasonal changes in abundance. Sixty-one unique viral OTUs, representing Megaviridae and Phycodnaviridae, showed only distant relationship with currently isolated algal viruses. Haptophyte and virus community composition and diversity varied substantially throughout the year, but in an uncoordinated manner. A minority of the viral OTUs were highly abundant at specific time-points, indicating a boom-bust relationship with their host. Most of the viral OTUs were very persistent, which may represent viruses that coexist with their hosts, or able to exploit several host species.
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23
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Ruiz E, Baudoux AC, Simon N, Sandaa RA, Thingstad TF, Pagarete A. Micromonas versus virus: New experimental insights challenge viral impact. Environ Microbiol 2017; 19:2068-2076. [DOI: 10.1111/1462-2920.13733] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2016] [Accepted: 03/13/2017] [Indexed: 11/27/2022]
Affiliation(s)
- Eliana Ruiz
- Department of Biology; University of Bergen; Bergen Norway
| | - Anne-Claire Baudoux
- CNRS, UMR 7144 (Adaptation et Diversité en Milieu Marin), Station Biologique de Roscoff; Sorbonne Universités; UPMC Univ Paris 06 Roscoff 29680 France
| | - Nathalie Simon
- CNRS, UMR 7144 (Adaptation et Diversité en Milieu Marin), Station Biologique de Roscoff; Sorbonne Universités; UPMC Univ Paris 06 Roscoff 29680 France
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24
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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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25
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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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26
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Heath SE, Knox K, Vale PF, Collins S. Virus Resistance Is Not Costly in a Marine Alga Evolving under Multiple Environmental Stressors. Viruses 2017; 9:v9030039. [PMID: 28282867 PMCID: PMC5371794 DOI: 10.3390/v9030039] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2017] [Revised: 02/24/2017] [Accepted: 02/28/2017] [Indexed: 01/21/2023] Open
Abstract
Viruses are important evolutionary drivers of host ecology and evolution. The marine picoplankton Ostreococcus tauri has three known resistance types that arise in response to infection with the Phycodnavirus OtV5: susceptible cells (S) that lyse following viral entry and replication; resistant cells (R) that are refractory to viral entry; and resistant producers (RP) that do not all lyse but maintain some viruses within the population. To test for evolutionary costs of maintaining antiviral resistance, we examined whether O. tauri populations composed of each resistance type differed in their evolutionary responses to several environmental drivers (lower light, lower salt, lower phosphate and a changing environment) in the absence of viruses for approximately 200 generations. We did not detect a cost of resistance as measured by life-history traits (population growth rate, cell size and cell chlorophyll content) and competitive ability. Specifically, all R and RP populations remained resistant to OtV5 lysis for the entire 200-generation experiment, whereas lysis occurred in all S populations, suggesting that resistance is not costly to maintain even when direct selection for resistance was removed, or that there could be a genetic constraint preventing return to a susceptible resistance type. Following evolution, all S population densities dropped when inoculated with OtV5, but not to zero, indicating that lysis was incomplete, and that some cells may have gained a resistance mutation over the evolution experiment. These findings suggest that maintaining resistance in the absence of viruses was not costly.
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Affiliation(s)
- Sarah E Heath
- Institute of Evolutionary Biology, School of Biological Sciences, University of Edinburgh, Ashworth Laboratories, The King's Buildings, Charlotte Auerbach Road, Edinburgh EH9 3FL, UK.
| | - Kirsten Knox
- Institute of Molecular Plant Sciences, School of Biological Sciences, University of Edinburgh, Rutherford Building, Max Born Crescent, Edinburgh EH9 3BF, UK.
| | - Pedro F Vale
- Institute of Evolutionary Biology, School of Biological Sciences, University of Edinburgh, Ashworth Laboratories, The King's Buildings, Charlotte Auerbach Road, Edinburgh EH9 3FL, UK.
| | - Sinead Collins
- Institute of Evolutionary Biology, School of Biological Sciences, University of Edinburgh, Ashworth Laboratories, The King's Buildings, Charlotte Auerbach Road, Edinburgh EH9 3FL, UK.
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27
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Demory D, Arsenieff L, Simon N, Six C, Rigaut-Jalabert F, Marie D, Ge P, Bigeard E, Jacquet S, Sciandra A, Bernard O, Rabouille S, Baudoux AC. Temperature is a key factor in Micromonas-virus interactions. ISME JOURNAL 2017; 11:601-612. [PMID: 28085157 DOI: 10.1038/ismej.2016.160] [Citation(s) in RCA: 31] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/30/2016] [Revised: 09/30/2016] [Accepted: 10/07/2016] [Indexed: 11/09/2022]
Abstract
The genus Micromonas comprises phytoplankton that show among the widest latitudinal distributions on Earth, and members of this genus are recurrently infected by prasinoviruses in contrasted thermal ecosystems. In this study, we assessed how temperature influences the interplay between the main genetic clades of this prominent microalga and their viruses. The growth of three Micromonas strains (Mic-A, Mic-B, Mic-C) and the stability of their respective lytic viruses (MicV-A, MicV-B, MicV-C) were measured over a thermal range of 4-32.5 °C. Similar growth temperature optima (Topt) were predicted for all three hosts but Mic-B exhibited a broader thermal tolerance than Mic-A and Mic-C, suggesting distinct thermoacclimation strategies. Similarly, the MicV-C virus displayed a remarkable thermal stability compared with MicV-A and MicV-B. Despite these divergences, infection dynamics showed that temperatures below Topt lengthened lytic cycle kinetics and reduced viral yield and, notably, that infection at temperatures above Topt did not usually result in cell lysis. Two mechanisms operated depending on the temperature and the biological system. Hosts either prevented the production of viral progeny or maintained their ability to produce virions with no apparent cell lysis, pointing to a possible switch in the viral life strategy. Hence, temperature changes critically affect the outcome of Micromonas infection and have implications for ocean biogeochemistry and evolution.
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Affiliation(s)
- David Demory
- Sorbonne Universités, UPMC Univ Paris 06, CNRS, Villefranche/mer, France.,BIOCORE-INRIA, BP93, Sophia-Antipolis Cedex, France
| | - Laure Arsenieff
- Sorbonne Universités, UPMC Univ Pierre et Marie Curie (Paris 06), CNRS, Adaptation et Diversité en Milieu Marin UMR7144, Station Biologique de Roscoff, Roscoff, France
| | - Nathalie Simon
- Sorbonne Universités, UPMC Univ Pierre et Marie Curie (Paris 06), CNRS, Adaptation et Diversité en Milieu Marin UMR7144, Station Biologique de Roscoff, Roscoff, France
| | - Christophe Six
- Sorbonne Universités, UPMC Univ Pierre et Marie Curie (Paris 06), CNRS, Adaptation et Diversité en Milieu Marin UMR7144, Station Biologique de Roscoff, Roscoff, France
| | - Fabienne Rigaut-Jalabert
- Sorbonne Universités, UPMC Univ Pierre et Marie Curie (Paris 06), CNRS, Fédération de Recherche FR2424, Station Biologique de Roscoff, Roscoff, France
| | - Dominique Marie
- Sorbonne Universités, UPMC Univ Pierre et Marie Curie (Paris 06), CNRS, Adaptation et Diversité en Milieu Marin UMR7144, Station Biologique de Roscoff, Roscoff, France
| | - Pei Ge
- Sorbonne Universités, UPMC Univ Pierre et Marie Curie (Paris 06), CNRS, Adaptation et Diversité en Milieu Marin UMR7144, Station Biologique de Roscoff, Roscoff, France
| | - Estelle Bigeard
- Sorbonne Universités, UPMC Univ Pierre et Marie Curie (Paris 06), CNRS, Adaptation et Diversité en Milieu Marin UMR7144, Station Biologique de Roscoff, Roscoff, France
| | | | - Antoine Sciandra
- Sorbonne Universités, UPMC Univ Paris 06, CNRS, Villefranche/mer, France
| | | | - Sophie Rabouille
- Sorbonne Universités, UPMC Univ Paris 06, CNRS, Villefranche/mer, France
| | - Anne-Claire Baudoux
- Sorbonne Universités, UPMC Univ Pierre et Marie Curie (Paris 06), CNRS, Adaptation et Diversité en Milieu Marin UMR7144, Station Biologique de Roscoff, Roscoff, France
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28
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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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29
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Heath SE, Collins S. Mode of resistance to viral lysis affects host growth across multiple environments in the marine picoeukaryote Ostreococcus tauri. Environ Microbiol 2016; 18:4628-4639. [PMID: 27768828 DOI: 10.1111/1462-2920.13586] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2016] [Accepted: 10/17/2016] [Indexed: 11/27/2022]
Abstract
Viruses play important roles in population dynamics and as drivers of evolution in single-celled marine phytoplankton. Viral infection of Ostreococcus tauri often causes cell lysis, but two spontaneously arising resistance mechanisms occur: resistant cells that cannot become infected and resistant producer cells that are infected but not lysed, and which may slowly release viruses. As of yet, little is known about how consistent the effects of viruses on their hosts are across different environments. To measure the effect of host resistance on host growth, and to determine whether this effect is environmentally dependent, we compared the growth and survival of susceptible, resistant and resistant producer O. tauri cells under five environmental conditions with and without exposure to O. tauri virus. While the effects of exposure to virus on growth rates did not show a consistent pattern in populations of resistant cells, there were several cases where exposure to virus affected growth in resistant hosts, sometimes positively. In the absence of virus, there was no detectable cost of resistance in any environment, as measured by growth rate. In fact, the opposite was the case, with populations of resistant producer cells having the highest growth rates across four of the five environments.
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Affiliation(s)
- Sarah E Heath
- Institute of Evolutionary Biology, School of Biological Sciences, University of Edinburgh, Ashworth Laboratories, The King's Buildings, West Mains Road, Edinburgh, EH9 3FL, UK
| | - Sinead Collins
- Institute of Evolutionary Biology, School of Biological Sciences, University of Edinburgh, Ashworth Laboratories, The King's Buildings, West Mains Road, Edinburgh, EH9 3FL, UK
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30
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Mirza S, Staniewski M, Short C, Long A, Chaban Y, Short S. Isolation and characterization of a virus infecting the freshwater algae Chrysochromulina parva. Virology 2015; 486:105-15. [DOI: 10.1016/j.virol.2015.09.005] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2015] [Revised: 08/26/2015] [Accepted: 09/08/2015] [Indexed: 11/26/2022]
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31
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Baudoux AC, Lebredonchel H, Dehmer H, Latimier M, Edern R, Rigaut-Jalabert F, Ge P, Guillou L, Foulon E, Bozec Y, Cariou T, Desdevises Y, Derelle E, Grimsley N, Moreau H, Simon N. Interplay between the genetic clades of Micromonas and their viruses in the Western English Channel. ENVIRONMENTAL MICROBIOLOGY REPORTS 2015; 7:765-773. [PMID: 26081716 DOI: 10.1111/1758-2229.12309] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/13/2015] [Revised: 05/13/2015] [Accepted: 06/04/2015] [Indexed: 06/04/2023]
Abstract
The genus Micromonas comprises distinct genetic clades that commonly dominate eukaryotic phytoplankton community from polar to tropical waters. This phytoplankter is also recurrently infected by abundant and genetically diverse prasinoviruses. Here we report on the interplay between prasinoviruses and Micromonas with regard to the genetic diversity of this host. For 1 year, we monitored the abundance of three clades of Micromonas and their viruses in the Western English Channel, both in the environment using clade-specific probes and flow cytometry, and in the laboratory using clonal strains of Micromonas clades to assay for their viruses by plaque-forming units. We showed that the seasonal fluctuations of Micromonas clades were closely mirrored by the abundance of their corresponding viruses, indicating that the members of Micromonas genus are susceptible to viral infection, regardless of their genetic affiliation. The characterization of 45 viral isolates revealed that Micromonas clades are attacked by specific virus populations, which exhibit distinctive clade specificity, life strategies and genetic diversity. However, some viruses can also cross-infect different host clades, suggesting a mechanism of horizontal gene transfer within the Micromonas genus. This study provides novel insights into the impact of viral infection for the ecology and evolution of the prominent phytoplankter Micromonas.
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Affiliation(s)
- A-C Baudoux
- Sorbonne Universités, UPMC Univ Paris 06, CNRS, Adaptation et Diversité en Milieu Marin (AD2M UMR7144), Station Biologique de Roscoff, 29680, Roscoff, France
| | - H Lebredonchel
- Sorbonne Universités, UPMC Univ Paris 06, CNRS, Biologie Intégrative des Organismes Marins (BIOM), Observatoire Océanologique, 66650, Banyuls sur Mer, France
| | - H Dehmer
- Sorbonne Universités, UPMC Univ Paris 06, CNRS, Adaptation et Diversité en Milieu Marin (AD2M UMR7144), Station Biologique de Roscoff, 29680, Roscoff, France
| | - M Latimier
- Sorbonne Universités, UPMC Univ Paris 06, CNRS, Adaptation et Diversité en Milieu Marin (AD2M UMR7144), Station Biologique de Roscoff, 29680, Roscoff, France
| | - R Edern
- Sorbonne Universités, UPMC Univ Paris 06, CNRS, Adaptation et Diversité en Milieu Marin (AD2M UMR7144), Station Biologique de Roscoff, 29680, Roscoff, France
| | - F Rigaut-Jalabert
- Sorbonne Universités, UPMC Univ Paris 06, CNRS, Fédération de Recherche (FR2424), Station Biologique de Roscoff, 29680, Roscoff, France
| | - P Ge
- Sorbonne Universités, UPMC Univ Paris 06, CNRS, Adaptation et Diversité en Milieu Marin (AD2M UMR7144), Station Biologique de Roscoff, 29680, Roscoff, France
| | - L Guillou
- Sorbonne Universités, UPMC Univ Paris 06, CNRS, Adaptation et Diversité en Milieu Marin (AD2M UMR7144), Station Biologique de Roscoff, 29680, Roscoff, France
| | - E Foulon
- Sorbonne Universités, UPMC Univ Paris 06, CNRS, Adaptation et Diversité en Milieu Marin (AD2M UMR7144), Station Biologique de Roscoff, 29680, Roscoff, France
| | - Y Bozec
- Sorbonne Universités, UPMC Univ Paris 06, CNRS, Adaptation et Diversité en Milieu Marin (AD2M UMR7144), Station Biologique de Roscoff, 29680, Roscoff, France
| | - T Cariou
- Sorbonne Universités, UPMC Univ Paris 06, CNRS, Fédération de Recherche (FR2424), Station Biologique de Roscoff, 29680, Roscoff, France
| | - Y Desdevises
- Sorbonne Universités, UPMC Univ Paris 06, CNRS, Biologie Intégrative des Organismes Marins (BIOM), Observatoire Océanologique, 66650, Banyuls sur Mer, France
| | - E Derelle
- Sorbonne Universités, UPMC Univ Paris 06, CNRS, Biologie Intégrative des Organismes Marins (BIOM), Observatoire Océanologique, 66650, Banyuls sur Mer, France
| | - N Grimsley
- Sorbonne Universités, UPMC Univ Paris 06, CNRS, Biologie Intégrative des Organismes Marins (BIOM), Observatoire Océanologique, 66650, Banyuls sur Mer, France
| | - H Moreau
- Sorbonne Universités, UPMC Univ Paris 06, CNRS, Biologie Intégrative des Organismes Marins (BIOM), Observatoire Océanologique, 66650, Banyuls sur Mer, France
| | - N Simon
- Sorbonne Universités, UPMC Univ Paris 06, CNRS, Adaptation et Diversité en Milieu Marin (AD2M UMR7144), Station Biologique de Roscoff, 29680, Roscoff, France
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32
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Tsv-N1: A Novel DNA Algal Virus that Infects Tetraselmis striata. Viruses 2015; 7:3937-53. [PMID: 26193304 PMCID: PMC4517135 DOI: 10.3390/v7072806] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2015] [Revised: 07/03/2015] [Accepted: 07/07/2015] [Indexed: 11/16/2022] Open
Abstract
Numbering in excess of 10 million per milliliter of water, it is now undisputed that aquatic viruses are one of the major factors shaping the ecology and evolution of Earth’s microbial world. Nonetheless, environmental viral diversity and roles remain poorly understood. Here we report the first thorough characterization of a virus (designated TsV) that infects the coastal marine microalga Tetraselmis striata. Unlike previously known microalgae-infecting viruses, TsV is a small (60 nm) DNA virus, with a 31 kb genome. From a range of eight different strains belonging to the Chlamydomonadaceae family, TsV was only able to infect T. striata. Gene expression dynamics revealed an up-regulation of viral transcripts already 1 h post-infection (p.i.). First clear signs of infection were observed 24 h p.i., with the appearance of viral factories inside the nucleus. TsV assembly was exclusively nuclear. TsV-N1 genome revealed very different from previously known algae viruses (Phycodnaviridae). Putative function and/or homology could be resolved for only 9 of the 33 ORFs encoded. Among those was a surprising DNA polymerase type Delta (only found in Eukaryotes), and two genes with closest homology to genes from human parasites of the urogenital tract. These results support the idea that the diversity of microalgae viruses goes far beyond the Phycodnaviridae family and leave the door open for future studies on implications of microalgae viruses for human health.
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33
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Pesant S, Not F, Picheral M, Kandels-Lewis S, Le Bescot N, Gorsky G, Iudicone D, Karsenti E, Speich S, Troublé R, Dimier C, Searson S. Open science resources for the discovery and analysis of Tara Oceans data. Sci Data 2015; 2:150023. [PMID: 26029378 PMCID: PMC4443879 DOI: 10.1038/sdata.2015.23] [Citation(s) in RCA: 194] [Impact Index Per Article: 21.6] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2015] [Accepted: 04/27/2015] [Indexed: 11/29/2022] Open
Abstract
The Tara Oceans expedition (2009–2013) sampled contrasting ecosystems of the world oceans, collecting environmental data and plankton, from viruses to metazoans, for later analysis using modern sequencing and state-of-the-art imaging technologies. It surveyed 210 ecosystems in 20 biogeographic provinces, collecting over 35,000 samples of seawater and plankton. The interpretation of such an extensive collection of samples in their ecological context requires means to explore, assess and access raw and validated data sets. To address this challenge, the Tara Oceans Consortium offers open science resources, including the use of open access archives for nucleotides (ENA) and for environmental, biogeochemical, taxonomic and morphological data (PANGAEA), and the development of on line discovery tools and collaborative annotation tools for sequences and images. Here, we present an overview of Tara Oceans Data, and we provide detailed registries (data sets) of all campaigns (from port-to-port), stations and sampling events.
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Affiliation(s)
- Stéphane Pesant
- PANGAEA, Data Publisher for Earth and Environmental Science , 28359 Bremen, Germany ; MARUM, Center for Marine Environmental Sciences, Universität Bremen , 28359 Bremen, Germany
| | - Fabrice Not
- CNRS, UMR 7144, Station Biologique de Roscoff , 29680 Roscoff, France ; Sorbonne Universités, UPMC Univ Paris 06, UMR 7144, Station Biologique de Roscoff , 29680 Roscoff, France
| | - Marc Picheral
- CNRS, UMR 7093, Observatoire Océanologique de Villefranche-sur-Mer (OOV) , 06230 Villefranche/mer, France ; Sorbonne Universités, UPMC Univ Paris 06, UMR 7093, Observatoire Océanologique de Villefranche-sur-Mer (OOV) , 06230, Villefranche/mer, France
| | - Stefanie Kandels-Lewis
- Structural and Computational Biology, European Molecular Biology Laboratory , Meyerhofstr. 1, 69117 Heidelberg, Germany ; Directors' Research, European Molecular Biology Laboratory Meyerhofstrasse 1 , 69117 Heidelberg, Germany
| | - Noan Le Bescot
- CNRS, UMR 7144, Station Biologique de Roscoff , 29680 Roscoff, France
| | - Gabriel Gorsky
- CNRS, UMR 7093, Observatoire Océanologique de Villefranche-sur-Mer (OOV) , 06230 Villefranche/mer, France ; Sorbonne Universités, UPMC Univ Paris 06, UMR 7093, Observatoire Océanologique de Villefranche-sur-Mer (OOV) , 06230, Villefranche/mer, France
| | - Daniele Iudicone
- Laboratory of Ecology and Evolution of Plankton, Stazione Zoologica Anton Dohrn , 80121 Naples, Italy
| | - Eric Karsenti
- Directors' Research, European Molecular Biology Laboratory Meyerhofstrasse 1 , 69117 Heidelberg, Germany ; Environmental and Evolutionary Genomics Section, Institut de Biologie de l'Ecole Normale Supérieure, CNRS, UMR 8197, Institut National de la Santé et de la Recherche Médicale U1024, Ecole Normale Supérieure , 75005 Paris, France
| | - Sabrina Speich
- Department of Geosciences, Laboratoire de Météorologie Dynamique (LMD), Ecole Normale Supérieure , 75005, Paris, France ; Laboratoire de Physique des Océan, UBO-IUEM , 29280 Polouzané, France
| | - Romain Troublé
- Tara Expéditions, Base Tara , 11 boulevard Bourdon, 75004 Paris, France
| | - Céline Dimier
- CNRS, UMR 7144, Station Biologique de Roscoff , 29680 Roscoff, France
| | - Sarah Searson
- Sorbonne Universités, UPMC Univ Paris 06, UMR 7144, Station Biologique de Roscoff , 29680 Roscoff, France ; Department of Oceanography, University of Hawaii at Manoa , Honolulu, HI 96822, USA
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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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Sime-Ngando T. Environmental bacteriophages: viruses of microbes in aquatic ecosystems. Front Microbiol 2014; 5:355. [PMID: 25104950 PMCID: PMC4109441 DOI: 10.3389/fmicb.2014.00355] [Citation(s) in RCA: 79] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2014] [Accepted: 06/25/2014] [Indexed: 11/29/2022] Open
Abstract
Since the discovery 2–3 decades ago that viruses of microbes are abundant in marine ecosystems, viral ecology has grown increasingly to reach the status of a full scientific discipline in environmental sciences. A dedicated ISVM society, the International Society for Viruses of Microorganisms, (http://www.isvm.org/) was recently launched. Increasing studies in viral ecology are sources of novel knowledge related to the biodiversity of living things, the functioning of ecosystems, and the evolution of the cellular world. This is because viruses are perhaps the most diverse, abundant, and ubiquitous biological entities in the biosphere, although local environmental conditions enrich for certain viral types through selective pressure. They exhibit various lifestyles that intimately depend on the deep-cellular mechanisms, and are ultimately replicated by members of all three domains of cellular life (Bacteria, Eukarya, Archaea), as well as by giant viruses of some eukaryotic cells. This establishes viral parasites as microbial killers but also as cell partners or metabolic manipulators in microbial ecology. The present chapter sought to review the literature on the diversity and functional roles of viruses of microbes in environmental microbiology, focusing primarily on prokaryotic viruses (i.e., phages) in aquatic ecosystems, which form the bulk of our knowledge in modern environmental viral ecology.
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Affiliation(s)
- Télesphore Sime-Ngando
- Laboratoire Microorganismes: Génome et Environnement, UMR CNRS 6023, Clermont Université Blaise Pascal Aubière, France
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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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Unveiling of the diversity of Prasinoviruses (Phycodnaviridae) in marine samples by using high-throughput sequencing analyses of PCR-amplified DNA polymerase and major capsid protein genes. Appl Environ Microbiol 2014; 80:3150-60. [PMID: 24632251 DOI: 10.1128/aem.00123-14] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Viruses strongly influence the ecology and evolution of their eukaryotic hosts in the marine environment, but little is known about their diversity and distribution. Prasinoviruses infect an abundant and widespread class of phytoplankton, the Mamiellophyceae, and thereby exert a specific and important role in microbial ecosystems. However, molecular tools to specifically identify this viral genus in environmental samples are still lacking. We developed two primer sets, designed for use with polymerase chain reactions and 454 pyrosequencing technologies, to target two conserved genes, encoding the DNA polymerase (PolB gene) and the major capsid protein (MCP gene). While only one copy of the PolB gene is present in Prasinovirus genomes, there are at least seven paralogs for MCP, the copy we named number 6 being shared with other eukaryotic alga-infecting viruses. Primer sets for PolB and MCP6 were thus designed and tested on 6 samples from the Tara Oceans project. The results suggest that the MCP6 amplicons show greater richness but that PolB gave a wider coverage of Prasinovirus diversity. As a consequence, we recommend use of the PolB primer set, which will certainly reveal exciting new insights about the diversity and distribution of prasinoviruses at the community scale.
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Martiny JBH, Riemann L, Marston MF, Middelboe M. Antagonistic coevolution of marine planktonic viruses and their hosts. ANNUAL REVIEW OF MARINE SCIENCE 2014; 6:393-414. [PMID: 23987913 DOI: 10.1146/annurev-marine-010213-135108] [Citation(s) in RCA: 50] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/12/2023]
Abstract
The potential for antagonistic coevolution between marine viruses and their (primarily bacterial) hosts is well documented, but our understanding of the consequences of this rapid evolution is in its infancy. Acquisition of resistance against co-occurring viruses and the subsequent evolution of virus host range in response have implications for bacterial mortality rates as well as for community composition and diversity. Drawing on examples from a range of environments, we consider the potential dynamics, underlying genetic mechanisms and fitness costs, and ecological impacts of virus-host coevolution in marine waters. Given that much of our knowledge is derived from laboratory experiments, we also discuss potential challenges and approaches in scaling up to diverse, complex networks of virus-host interactions. Finally, we note that a variety of novel approaches for characterizing virus-host interactions offer new hope for a mechanistic understanding of antagonistic coevolution in marine plankton.
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Affiliation(s)
- Jennifer B H Martiny
- Department of Ecology and Evolutionary Biology, University of California, Irvine, California 92697;
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Cray JA, Bell ANW, Bhaganna P, Mswaka AY, Timson DJ, Hallsworth JE. The biology of habitat dominance; can microbes behave as weeds? Microb Biotechnol 2013; 6:453-92. [PMID: 23336673 PMCID: PMC3918151 DOI: 10.1111/1751-7915.12027] [Citation(s) in RCA: 160] [Impact Index Per Article: 14.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2012] [Accepted: 12/03/2012] [Indexed: 02/06/2023] Open
Abstract
Competition between microbial species is a product of, yet can lead to a reduction in, the microbial diversity of specific habitats. Microbial habitats can resemble ecological battlefields where microbial cells struggle to dominate and/or annihilate each other and we explore the hypothesis that (like plant weeds) some microbes are genetically hard-wired to behave in a vigorous and ecologically aggressive manner. These 'microbial weeds' are able to dominate the communities that develop in fertile but uncolonized--or at least partially vacant--habitats via traits enabling them to out-grow competitors; robust tolerances to habitat-relevant stress parameters and highly efficient energy-generation systems; avoidance of or resistance to viral infection, predation and grazers; potent antimicrobial systems; and exceptional abilities to sequester and store resources. In addition, those associated with nutritionally complex habitats are extraordinarily versatile in their utilization of diverse substrates. Weed species typically deploy multiple types of antimicrobial including toxins; volatile organic compounds that act as either hydrophobic or highly chaotropic stressors; biosurfactants; organic acids; and moderately chaotropic solutes that are produced in bulk quantities (e.g. acetone, ethanol). Whereas ability to dominate communities is habitat-specific we suggest that some microbial species are archetypal weeds including generalists such as: Pichia anomala, Acinetobacter spp. and Pseudomonas putida; specialists such as Dunaliella salina, Saccharomyces cerevisiae, Lactobacillus spp. and other lactic acid bacteria; freshwater autotrophs Gonyostomum semen and Microcystis aeruginosa; obligate anaerobes such as Clostridium acetobutylicum; facultative pathogens such as Rhodotorula mucilaginosa, Pantoea ananatis and Pseudomonas aeruginosa; and other extremotolerant and extremophilic microbes such as Aspergillus spp., Salinibacter ruber and Haloquadratum walsbyi. Some microbes, such as Escherichia coli, Mycobacterium smegmatis and Pseudoxylaria spp., exhibit characteristics of both weed and non-weed species. We propose that the concept of nonweeds represents a 'dustbin' group that includes species such as Synodropsis spp., Polypaecilum pisce, Metschnikowia orientalis, Salmonella spp., and Caulobacter crescentus. We show that microbial weeds are conceptually distinct from plant weeds, microbial copiotrophs, r-strategists, and other ecophysiological groups of microorganism. Microbial weed species are unlikely to emerge from stationary-phase or other types of closed communities; it is open habitats that select for weed phenotypes. Specific characteristics that are common to diverse types of open habitat are identified, and implications of weed biology and open-habitat ecology are discussed in the context of further studies needed in the fields of environmental and applied microbiology.
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Affiliation(s)
- Jonathan A Cray
- School of Biological Sciences, MBC, Queen's University BelfastBelfast, BT9 7BL, Northern Ireland, UK
| | - Andrew N W Bell
- School of Biological Sciences, MBC, Queen's University BelfastBelfast, BT9 7BL, Northern Ireland, UK
| | - Prashanth Bhaganna
- School of Biological Sciences, MBC, Queen's University BelfastBelfast, BT9 7BL, Northern Ireland, UK
| | - Allen Y Mswaka
- School of Biological Sciences, MBC, Queen's University BelfastBelfast, BT9 7BL, Northern Ireland, UK
| | - David J Timson
- School of Biological Sciences, MBC, Queen's University BelfastBelfast, BT9 7BL, Northern Ireland, UK
| | - John E Hallsworth
- School of Biological Sciences, MBC, Queen's University BelfastBelfast, BT9 7BL, Northern Ireland, UK
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40
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Subirana L, Péquin B, Michely S, Escande ML, Meilland J, Derelle E, Marin B, Piganeau G, Desdevises Y, Moreau H, Grimsley NH. Morphology, Genome Plasticity, and Phylogeny in the Genus Ostreococcus Reveal a Cryptic Species, O. mediterraneus sp. nov. (Mamiellales, Mamiellophyceae). Protist 2013; 164:643-59. [PMID: 23892412 DOI: 10.1016/j.protis.2013.06.002] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2011] [Revised: 05/27/2013] [Accepted: 06/18/2013] [Indexed: 01/16/2023]
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Gaudin M, Krupovic M, Marguet E, Gauliard E, Cvirkaite-Krupovic V, Le Cam E, Oberto J, Forterre P. Extracellular membrane vesicles harbouring viral genomes. Environ Microbiol 2013; 16:1167-75. [DOI: 10.1111/1462-2920.12235] [Citation(s) in RCA: 61] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2013] [Revised: 07/25/2013] [Accepted: 07/28/2013] [Indexed: 12/31/2022]
Affiliation(s)
- Marie Gaudin
- CNRS UMR 8621; Institut de Génétique et Microbiologie; Univ Paris-Sud; 91405 Orsay cedex France
| | - Mart Krupovic
- Biologie Moléculaire du Gène chez les Extrêmophiles; Département de Microbiologie; Institut Pasteur; 75724 Paris cedex France
| | - Evelyne Marguet
- CNRS UMR 8621; Institut de Génétique et Microbiologie; Univ Paris-Sud; 91405 Orsay cedex France
| | - Emilie Gauliard
- CNRS UMR 8621; Institut de Génétique et Microbiologie; Univ Paris-Sud; 91405 Orsay cedex France
| | | | - Eric Le Cam
- Signalisation; Noyaux et Innovations en Cancérologie; Interactions Moléculaires et Cancer; CNRS UMR 8126; Institut de Cancérologie Gustave Roussy 94805 Villejuif cedex France
| | - Jacques Oberto
- CNRS UMR 8621; Institut de Génétique et Microbiologie; Univ Paris-Sud; 91405 Orsay cedex France
| | - Patrick Forterre
- CNRS UMR 8621; Institut de Génétique et Microbiologie; Univ Paris-Sud; 91405 Orsay cedex France
- Biologie Moléculaire du Gène chez les Extrêmophiles; Département de Microbiologie; Institut Pasteur; 75724 Paris cedex France
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Rowe JM, Dunigan DD, Blanc G, Gurnon JR, Xia Y, Van Etten JL. Evaluation of higher plant virus resistance genes in the green alga, Chlorella variabilis NC64A, during the early phase of infection with Paramecium bursaria chlorella virus-1. Virology 2013; 442:101-13. [PMID: 23701839 PMCID: PMC4107423 DOI: 10.1016/j.virol.2013.04.018] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2013] [Revised: 04/18/2013] [Accepted: 04/20/2013] [Indexed: 01/25/2023]
Abstract
With growing industrial interest in algae plus their critical roles in aquatic systems, the need to understand the effects of algal pathogens is increasing. We examined a model algal host-virus system, Chlorella variabilis NC64A and virus, PBCV-1. C. variabilis encodes 375 homologs to genes involved in RNA silencing and in response to virus infection in higher plants. Illumina RNA-Seq data showed that 325 of these homologs were expressed in healthy and early PBCV-1 infected (≤60min) cells. For each of the RNA silencing genes to which homologs were found, mRNA transcripts were detected in healthy and infected cells. C. variabilis, like higher plants, may employ certain RNA silencing pathways to defend itself against virus infection. To our knowledge this is the first examination of RNA silencing genes in algae beyond core proteins, and the first analysis of their transcription during virus infection.
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Affiliation(s)
- Janet M. Rowe
- Department of Plant Pathology, University of Nebraska, Lincoln, NE 68583-0900, United States
- Nebraska Center for Virology, University of Nebraska, Lincoln, NE 68583-0900, United States
| | - David D. Dunigan
- Department of Plant Pathology, University of Nebraska, Lincoln, NE 68583-0900, United States
- Nebraska Center for Virology, University of Nebraska, Lincoln, NE 68583-0900, United States
| | - Guillaume Blanc
- Structural and Génomique Information Laboratoire, UMR7256 CNRS, Aix-Marseille Université, Marseille, FR-13385, France
| | - James R. Gurnon
- Department of Plant Pathology, University of Nebraska, Lincoln, NE 68583-0900, United States
- Nebraska Center for Virology, University of Nebraska, Lincoln, NE 68583-0900, United States
| | - Yuannan Xia
- Center for Biotechnology, University of Nebraska, Lincoln, NE 68588-0665, United States
| | - James L. Van Etten
- Department of Plant Pathology, University of Nebraska, Lincoln, NE 68583-0900, United States
- Nebraska Center for Virology, University of Nebraska, Lincoln, NE 68583-0900, United States
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Moreau H, Verhelst B, Couloux A, Derelle E, Rombauts S, Grimsley N, Van Bel M, Poulain J, Katinka M, Hohmann-Marriott MF, Piganeau G, Rouzé P, Da Silva C, Wincker P, Van de Peer Y, Vandepoele K. Gene functionalities and genome structure in Bathycoccus prasinos reflect cellular specializations at the base of the green lineage. Genome Biol 2012; 13:R74. [PMID: 22925495 PMCID: PMC3491373 DOI: 10.1186/gb-2012-13-8-r74] [Citation(s) in RCA: 105] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2012] [Accepted: 08/24/2012] [Indexed: 12/18/2022] Open
Abstract
BACKGROUND Bathycoccus prasinos is an extremely small cosmopolitan marine green alga whose cells are covered with intricate spider's web patterned scales that develop within the Golgi cisternae before their transport to the cell surface. The objective of this work is to sequence and analyze its genome, and to present a comparative analysis with other known genomes of the green lineage. RESEARCH Its small genome of 15 Mb consists of 19 chromosomes and lacks transposons. Although 70% of all B. prasinos genes share similarities with other Viridiplantae genes, up to 428 genes were probably acquired by horizontal gene transfer, mainly from other eukaryotes. Two chromosomes, one big and one small, are atypical, an unusual synapomorphic feature within the Mamiellales. Genes on these atypical outlier chromosomes show lower GC content and a significant fraction of putative horizontal gene transfer genes. Whereas the small outlier chromosome lacks colinearity with other Mamiellales and contains many unknown genes without homologs in other species, the big outlier shows a higher intron content, increased expression levels and a unique clustering pattern of housekeeping functionalities. Four gene families are highly expanded in B. prasinos, including sialyltransferases, sialidases, ankyrin repeats and zinc ion-binding genes, and we hypothesize that these genes are associated with the process of scale biogenesis. CONCLUSION The minimal genomes of the Mamiellophyceae provide a baseline for evolutionary and functional analyses of metabolic processes in green plants.
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Clerissi C, Grimsley N, Desdevises Y. GENETIC EXCHANGES OF INTEINS BETWEENPRASINOVIRUSES(PHYCODNAVIRIDAE). Evolution 2012; 67:18-33. [DOI: 10.1111/j.1558-5646.2012.01738.x] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Abstract
Because viruses of eukaryotic algae are incredibly diverse, sweeping generalizations about their ecology are rare. These obligate parasites infect a range of algae and their diversity can be illustrated by considering that isolates range from small particles with ssRNA genomes to much larger particles with 560 kb dsDNA genomes. Molecular research has also provided clues about the extent of their diversity especially considering that genetic signatures of algal viruses in the environment rarely match cultivated viruses. One general concept in algal virus ecology that has emerged is that algal viruses are very host specific and most infect only certain strains of their hosts; with the exception of viruses of brown algae, evidence for interspecies infectivity is lacking. Although some host-virus systems behave with boom-bust oscillations, complex patterns of intraspecies infectivity can lead to host-virus coexistence obfuscating the role of viruses in host population dynamics. Within the framework of population dynamics, host density dependence is an important phenomenon that influences virus abundances in nature. Variable burst sizes of different viruses also influence their abundances and permit speculations about different life strategies, but as exceptions are common in algal virus ecology, life strategy generalizations may not be broadly applicable. Gaps in knowledge of virus seasonality and persistence are beginning to close and investigations of environmental reservoirs and virus resilience may answer questions about virus inter-annual recurrences. Studies of algal mortality have shown that viruses are often important agents of mortality reinforcing notions about their ecological relevance, while observations of the surprising ways viruses interact with their hosts highlight the immaturity of our understanding. Considering that just two decades ago algal viruses were hardly acknowledged, recent progress affords the optimistic perspective that future studies will provide keys to unlocking our understanding of algal virus ecology specifically, and aquatic ecosystems generally.
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Affiliation(s)
- Steven M Short
- Department of Biology, University of Toronto Mississauga, Mississauga, Canada.
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Prasinoviruses of the marine green alga Ostreococcus tauri are mainly species specific. J Virol 2012; 86:4611-9. [PMID: 22318150 DOI: 10.1128/jvi.07221-11] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Prasinoviruses infecting unicellular green algae in the order Mamiellales (class Mamiellophyceae) are commonly found in coastal marine waters where their host species frequently abound. We tested 40 Ostreococcus tauri viruses on 13 independently isolated wild-type O. tauri strains, 4 wild-type O. lucimarinus strains, 1 Ostreococcus sp. ("Ostreococcus mediterraneus") clade D strain, and 1 representative species of each of two other related species of Mamiellales, Bathycoccus prasinos and Micromonas pusilla. Thirty-four out of 40 viruses infected only O. tauri, 5 could infect one other species of the Ostreococcus genus, and 1 infected two other Ostreococcus spp., but none of them infected the other genera. We observed that the overall susceptibility pattern of Ostreococcus strains to viruses was related to the size of two host chromosomes known to show intraspecific size variations, that genetically related viruses tended to infect the same host strains, and that viruses carrying inteins were strictly strain specific. Comparison of two complete O. tauri virus proteomes revealed at least three predicted proteins to be candidate viral specificity determinants.
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47
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A chemical arms race at sea mediates algal host–virus interactions. Curr Opin Microbiol 2011; 14:449-57. [PMID: 21816665 DOI: 10.1016/j.mib.2011.07.013] [Citation(s) in RCA: 48] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2011] [Accepted: 07/05/2011] [Indexed: 01/28/2023]
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