A Viral Immunity Chromosome in the Marine Picoeukaryote, Ostreococcus tauri

Archive ouverte

Yau, Sheree | Hemon, Claire | Derelle, Evelyne | Moreau, Hervé | Piganeau, Gwenaë, L | Grimsley, Nigel

Edité par CCSD ; Public Library of Science -

International audience. 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.

Suggestions

Du même auteur

Genome Analyses of the Microalga Picochlorum Provide Insights into the Evolution of Thermotolerance in the Green Lineage

Archive ouverte | Krasovec, Marc | CCSD

International audience

Virus-host coexistence in phytoplankton through the genomic lens

Archive ouverte | Yau, Sheree | CCSD

International audience. 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, ...

Prasinovirus Attack of Ostreococcus Is Furtive by Day but Savage by Night

Archive ouverte | Derelle, Evelyne | CCSD

International audience

Chargement des enrichissements...