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Reverse transcriptase genes are highly abundant and transcriptionally active in marine plankton assemblages

11/27/2015
The ISME Journal
10 pp. 1134-1146

Type

Article dans des revues

Authors

Lescot Magali
Hingamp Pascal
Kojima Kenji K
Villar Emilie
Romac Sarah
Veluchamy Alaguraj
Boccara Martine
Jaillon Olivier
Iudicone Daniele
Bowler Chris
Wincker Patrick
Claverie Jean-Michel
Ogata Hiroyuki

Genes encoding reverse transcriptases (RTs) are found in most eukaryotes, often as a component of retrotransposons, as well as in retroviruses and in prokaryotic retroelements. We investigated the abundance, classification and transcriptional status of RTs based on Tara Oceans marine metagenomes and metatranscriptomes encompassing a wide organism size range. Our analyses revealed that RTs predominate large-size fraction metagenomes (45μm), where they reached a maximum of 13.5% of the total gene abundance. Metagenomic RTs were widely distributed across the phylogeny of known RTs, but many belonged to previously uncharacterized clades. Metatranscrip- tomic RTs showed distinct abundance patterns across samples compared with metagenomic RTs. The relative abundances of viral and bacterial RTs among identified RT sequences were higher in metatranscriptomes than in metagenomes and these sequences were detected in all metatran- scriptome size fractions. Overall, these observations suggest an active proliferation of various RT-assisted elements, which could be involved in genome evolution or adaptive processes of plankton assemblage.