title: Temperature is a key factor in Micromonas-virus interactions.
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 Toptlengthened lytic cycle kinetics and reduced viral yield and, notably, that infection at temperatures above Toptdid 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.
authors.affiliation: Sorbonne Universités, UPMC Univ Paris 06, CNRS, Villefranche/mer, France.|BIOCORE-INRIA, BP93, Sophia-Antipolis Cedex, France.
authors.forename: David
authors.initials: D
authors.lastname: Demory
authors.affiliation: Sorbonne Universités, UPMC Univ Pierre et Marie Curie (Paris 06), CNRS, Adaptation et Diversité en Milieu Marin UMR7144, Station Biologique de Roscoff, Roscoff, France.
authors.forename: Laure
authors.initials: L
authors.lastname: Arsenieff
authors.affiliation: Sorbonne Universités, UPMC Univ Pierre et Marie Curie (Paris 06), CNRS, Adaptation et Diversité en Milieu Marin UMR7144, Station Biologique de Roscoff, Roscoff, France.
authors.forename: Nathalie
authors.initials: N
authors.lastname: Simon
authors.affiliation: Sorbonne Universités, UPMC Univ Pierre et Marie Curie (Paris 06), CNRS, Adaptation et Diversité en Milieu Marin UMR7144, Station Biologique de Roscoff, Roscoff, France.
authors.forename: Christophe
authors.initials: C
authors.lastname: Six
authors.affiliation: Sorbonne Universités, UPMC Univ Pierre et Marie Curie (Paris 06), CNRS, Fédération de Recherche FR2424, Station Biologique de Roscoff, Roscoff, France.
authors.forename: Fabienne
authors.initials: F
authors.lastname: Rigaut-Jalabert
authors.affiliation: Sorbonne Universités, UPMC Univ Pierre et Marie Curie (Paris 06), CNRS, Adaptation et Diversité en Milieu Marin UMR7144, Station Biologique de Roscoff, Roscoff, France.
authors.forename: Dominique
authors.initials: D
authors.lastname: Marie
authors.affiliation: Sorbonne Universités, UPMC Univ Pierre et Marie Curie (Paris 06), CNRS, Adaptation et Diversité en Milieu Marin UMR7144, Station Biologique de Roscoff, Roscoff, France.
authors.forename: Pei
authors.initials: P
authors.lastname: Ge
authors.affiliation: Sorbonne Universités, UPMC Univ Pierre et Marie Curie (Paris 06), CNRS, Adaptation et Diversité en Milieu Marin UMR7144, Station Biologique de Roscoff, Roscoff, France.
authors.forename: Estelle
authors.initials: E
authors.lastname: Bigeard
authors.affiliation: INRA, UMR CARRTEL, Thonon-les-Bains Cedex, France.
authors.forename: Stéphan
authors.initials: S
authors.lastname: Jacquet
authors.affiliation: Sorbonne Universités, UPMC Univ Paris 06, CNRS, Villefranche/mer, France.
authors.forename: Antoine
authors.initials: A
authors.lastname: Sciandra
authors.affiliation: BIOCORE-INRIA, BP93, Sophia-Antipolis Cedex, France.
authors.forename: Olivier
authors.initials: O
authors.lastname: Bernard
authors.affiliation: Sorbonne Universités, UPMC Univ Paris 06, CNRS, Villefranche/mer, France.
authors.forename: Sophie
authors.initials: S
authors.lastname: Rabouille
authors.affiliation: Sorbonne Universités, UPMC Univ Pierre et Marie Curie (Paris 06), CNRS, Adaptation et Diversité en Milieu Marin UMR7144, Station Biologique de Roscoff, Roscoff, France.
authors.forename: Anne-Claire
authors.initials: AC
authors.lastname: Baudoux
mesh_terms: D000460:Chlorophyta / Q000254:growth & development / Q000821:virology*; D017753:Ecosystem; D054884:Host-Pathogen Interactions; D017862:Phycodnaviridae / Q000145:classification / Q000235:genetics / Q000502:physiology*; D010839:Phytoplankton / Q000254:growth & development / Q000821:virology; D012623:Seawater; D013696:Temperature; D014771:Virion / Q000502:physiology