Horizontal transfer and evolution of transposable elements in animals

SémIDEEV à GQE-Le Moulon

Vendredi 20 mars 2020 à 12h00

Salle de conférences de l’UMR - Ferme du Moulon, Gif-sur-Yvette

Clément GILBERT

(EGCE, CNRS, Gif-sur-Yvette)

invité par Clémentine Vitte

Horizontal transfer and evolution of transposable elements in animals

Abstract

Horizontal transfer (HT) of genetic material is central to the architecture and evolution of prokaryote genomes. Within eukaryotes, the majority of HTs reported so far are transfers of transposable elements (TEs). These reports essentially come from studies focusing on specific lineages or types of TEs. Because of the lack of large-scale survey, the amount and impact of HT of TEs (HTT) in eukaryote evolution, as well as the trends and factors shaping these transfers, are poorly known.

Here, I will report the results of our recent comprehensive analyses of HTT in 195 insect and 307 vertebrate genomes. We developed a pipeline to detect and count HTT events which allowed us to infer a minimum of 975 and 2,248 independent HTT in vertebrates and insects respectively. We show that DNA transposons transfer horizontally more often than retrotransposons, and unveil phylogenetic relatedness and geographical proximity as major factors facilitating HTT in insects. We also show that host taxa play an important role in shaping HTT by identifying Lepidoptera and ray-finned fishes as hotspots of transfers. Even though our study is restricted to a small fraction of animal diversity and to a recent evolutionary timeframe, the TEs we found to be horizontally transferred generated an important fraction of insect and vertebrate genomes. Together, our results establish HTT as a major force shaping animal genome evolution.