Interplay between the genetic clades of ¡i¿Micromonas¡/i¿ and their viruses in the Western English Channel.

TitleInterplay between the genetic clades of ¡i¿Micromonas¡/i¿ and their viruses in the Western English Channel.
Publication TypeJournal Article
Year of Publication2015
AuthorsBaudoux A-C, 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
JournalEnvironmental microbiology reports
Date Publishedjun
Keywords2015, rcc, RCC?o?dd, sbr?hyto$_\textrmd$ipo

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 regards to the genetic diversity of this host. During one year, we monitored the abundance of 3 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 abundances 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 Micromonas genus. This study provides novel insights into the impact of viral infection for the ecology and evolution of the prominent phytoplankter Micromonas.