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Zhang J, Yan Y, Shi J. Modelling phytoplankton-virus interactions: phytoplankton blooms and lytic virus transmission. J Math Biol 2024; 88:77. [PMID: 38695878 PMCID: PMC11065791 DOI: 10.1007/s00285-024-02093-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2023] [Revised: 01/17/2024] [Accepted: 04/08/2024] [Indexed: 05/05/2024]
Abstract
A dynamic reaction-diffusion model of four variables is proposed to describe the spread of lytic viruses among phytoplankton in a poorly mixed aquatic environment. The basic ecological reproductive index for phytoplankton invasion and the basic reproduction number for virus transmission are derived to characterize the phytoplankton growth and virus transmission dynamics. The theoretical and numerical results from the model show that the spread of lytic viruses effectively controls phytoplankton blooms. This validates the observations and experimental results of Emiliana huxleyi-lytic virus interactions. The studies also indicate that the lytic virus transmission cannot occur in a low-light or oligotrophic aquatic environment.
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Affiliation(s)
- Jimin Zhang
- School of Mathematical Sciences, Heilongjiang University, Harbin, 150080, Heilongjiang, People's Republic of China
| | - Yawen Yan
- School of Mathematical Sciences, Heilongjiang University, Harbin, 150080, Heilongjiang, People's Republic of China
| | - Junping Shi
- Department of Mathematics, William & Mary, Williamsburg, VA, 23187-8795, USA.
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2
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Lievens EJP, Agarkova IV, Dunigan DD, Van Etten JL, Becks L. Efficient assays to quantify the life history traits of algal viruses. Appl Environ Microbiol 2023; 89:e0165923. [PMID: 38092674 PMCID: PMC10734466 DOI: 10.1128/aem.01659-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2023] [Accepted: 09/27/2023] [Indexed: 12/22/2023] Open
Abstract
IMPORTANCE Viruses play a crucial role in microbial ecosystems by liberating nutrients and regulating the growth of their hosts. These effects are governed by viral life history traits, i.e., by the traits determining viral reproduction and survival. Understanding these traits is essential to predicting viral effects, but measuring them is generally labor intensive. In this study, we present efficient methods to quantify the full life cycle of lytic viruses. We developed these methods for viruses infecting unicellular Chlorella algae but expect them to be applicable to other lytic viruses that can be quantified by flow cytometry. By making viral phenotypes accessible, our methods will support research into the diversity and ecological effects of microbial viruses.
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Affiliation(s)
- Eva J. P. Lievens
- Aquatic Ecology and Evolution Group, Limnological Institute, University of Konstanz, Konstanz, Germany
| | - Irina V. Agarkova
- Department of Plant Pathology, University of Nebraska-Lincoln, Lincoln, Nebraska, USA
- Nebraska Center for Virology, University of Nebraska-Lincoln, Lincoln, Nebraska, USA
| | - David D. Dunigan
- Department of Plant Pathology, University of Nebraska-Lincoln, Lincoln, Nebraska, USA
- Nebraska Center for Virology, University of Nebraska-Lincoln, Lincoln, Nebraska, USA
| | - James L. Van Etten
- Department of Plant Pathology, University of Nebraska-Lincoln, Lincoln, Nebraska, USA
- Nebraska Center for Virology, University of Nebraska-Lincoln, Lincoln, Nebraska, USA
| | - Lutz Becks
- Aquatic Ecology and Evolution Group, Limnological Institute, University of Konstanz, Konstanz, Germany
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3
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Meng L, Delmont TO, Gaïa M, Pelletier E, Fernàndez-Guerra A, Chaffron S, Neches RY, Wu J, Kaneko H, Endo H, Ogata H. Genomic adaptation of giant viruses in polar oceans. Nat Commun 2023; 14:6233. [PMID: 37828003 PMCID: PMC10570341 DOI: 10.1038/s41467-023-41910-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2023] [Accepted: 09/24/2023] [Indexed: 10/14/2023] Open
Abstract
Despite being perennially frigid, polar oceans form an ecosystem hosting high and unique biodiversity. Various organisms show different adaptive strategies in this habitat, but how viruses adapt to this environment is largely unknown. Viruses of phyla Nucleocytoviricota and Mirusviricota are groups of eukaryote-infecting large and giant DNA viruses with genomes encoding a variety of functions. Here, by leveraging the Global Ocean Eukaryotic Viral database, we investigate the biogeography and functional repertoire of these viruses at a global scale. We first confirm the existence of an ecological barrier that clearly separates polar and nonpolar viral communities, and then demonstrate that temperature drives dramatic changes in the virus-host network at the polar-nonpolar boundary. Ancestral niche reconstruction suggests that adaptation of these viruses to polar conditions has occurred repeatedly over the course of evolution, with polar-adapted viruses in the modern ocean being scattered across their phylogeny. Numerous viral genes are specifically associated with polar adaptation, although most of their homologues are not identified as polar-adaptive genes in eukaryotes. These results suggest that giant viruses adapt to cold environments by changing their functional repertoire, and this viral evolutionary strategy is distinct from the polar adaptation strategy of their hosts.
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Affiliation(s)
- Lingjie Meng
- Bioinformatics Center, Institute for Chemical Research, Kyoto University, Gokasho, Uji, 611-0011, Japan
| | - Tom O Delmont
- Génomique Métabolique, Genoscope, Institut François Jacob, CEA, CNRS, Univ Evry, Université Paris-Saclay, F-91057, Evry, France
- Research Federation for the study of Global Ocean systems ecology and evolution, FR2022/Tara GOsee, F-75016, Paris, France
| | - Morgan Gaïa
- Génomique Métabolique, Genoscope, Institut François Jacob, CEA, CNRS, Univ Evry, Université Paris-Saclay, F-91057, Evry, France
- Research Federation for the study of Global Ocean systems ecology and evolution, FR2022/Tara GOsee, F-75016, Paris, France
| | - Eric Pelletier
- Génomique Métabolique, Genoscope, Institut François Jacob, CEA, CNRS, Univ Evry, Université Paris-Saclay, F-91057, Evry, France
- Research Federation for the study of Global Ocean systems ecology and evolution, FR2022/Tara GOsee, F-75016, Paris, France
| | - Antonio Fernàndez-Guerra
- Lundbeck Foundation GeoGenetics Centre, GLOBE Institute, University of Copenhagen, Copenhagen, Denmark
| | - Samuel Chaffron
- Research Federation for the study of Global Ocean systems ecology and evolution, FR2022/Tara GOsee, F-75016, Paris, France
- Nantes Université, École Centrale Nantes, CNRS, LS2N, UMR 6004, F-44000, Nantes, France
| | - Russell Y Neches
- Bioinformatics Center, Institute for Chemical Research, Kyoto University, Gokasho, Uji, 611-0011, Japan
| | - Junyi Wu
- Bioinformatics Center, Institute for Chemical Research, Kyoto University, Gokasho, Uji, 611-0011, Japan
| | - Hiroto Kaneko
- Bioinformatics Center, Institute for Chemical Research, Kyoto University, Gokasho, Uji, 611-0011, Japan
| | - Hisashi Endo
- Bioinformatics Center, Institute for Chemical Research, Kyoto University, Gokasho, Uji, 611-0011, Japan
| | - Hiroyuki Ogata
- Bioinformatics Center, Institute for Chemical Research, Kyoto University, Gokasho, Uji, 611-0011, Japan.
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4
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Abstract
Viruses are the most abundant biological entity in the ocean and infect a wide range of microbial life across bacteria, archaea, and eukaryotes. In this essay, we take a journey across several orders of magnitude in the scales of biological organization, time, and space of host-virus interactions in the ocean, aiming to shed light on their ecological relevance. We start from viruses infecting microbial host cells by delivering their genetic material in seconds across nanometer-size membranes, which highjack their host's metabolism in a few minutes to hours, leading to a profound transcriptomic and metabolic rewiring. The outcome of lytic infection leads to a release of virions and signaling molecules that can reach neighboring cells a few millimeters away, resulting in a population whose heterogeneous infection level impacts the surrounding community for days. These population dynamics can leave unique metabolic and biogeochemical fingerprints across scales of kilometers and over several decades. One of the biggest challenges in marine microbiology is to assess the impact of viruses across these scales, from the single cell to the ecosystem level. Here, we argue that the advent of new methodologies and conceptual frameworks represents an exciting time to pursue these efforts and propose a set of important challenges for the field. A better understanding of host-virus interactions across scales will inform models of global ocean ecosystem function in different climate change scenarios.
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Affiliation(s)
- Flora Vincent
- Department of Plant and Environmental Sciences, Weizmann Institute of Science, Rehovot, Israel
| | - Assaf Vardi
- Department of Plant and Environmental Sciences, Weizmann Institute of Science, Rehovot, Israel
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Viruses affect picocyanobacterial abundance and biogeography in the North Pacific Ocean. Nat Microbiol 2022; 7:570-580. [PMID: 35365792 PMCID: PMC8975747 DOI: 10.1038/s41564-022-01088-x] [Citation(s) in RCA: 17] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2021] [Accepted: 02/22/2022] [Indexed: 11/09/2022]
Abstract
The photosynthetic picocyanobacteria Prochlorococcus and Synechococcus are models for dissecting how ecological niches are defined by environmental conditions, but how interactions with bacteriophages affect picocyanobacterial biogeography in open ocean biomes has rarely been assessed. We applied single-virus and single-cell infection approaches to quantify cyanophage abundance and infected picocyanobacteria in 87 surface water samples from five transects that traversed approximately 2,200 km in the North Pacific Ocean on three cruises, with a duration of 2-4 weeks, between 2015 and 2017. We detected a 550-km-wide hotspot of cyanophages and virus-infected picocyanobacteria in the transition zone between the North Pacific Subtropical and Subpolar gyres that was present in each transect. Notably, the hotspot occurred at a consistent temperature and displayed distinct cyanophage-lineage composition on all transects. On two of these transects, the levels of infection in the hotspot were estimated to be sufficient to substantially limit the geographical range of Prochlorococcus. Coincident with the detection of high levels of virally infected picocyanobacteria, we measured an increase of 10-100-fold in the Synechococcus populations in samples that are usually dominated by Prochlorococcus. We developed a multiple regression model of cyanophages, temperature and chlorophyll concentrations that inferred that the hotspot extended across the North Pacific Ocean, creating a biological boundary between gyres, with the potential to release organic matter comparable to that of the sevenfold-larger North Pacific Subtropical Gyre. Our results highlight the probable impact of viruses on large-scale phytoplankton biogeography and biogeochemistry in distinct regions of the oceans.
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