Un rétrovirus endogène actif et infectieux : le cas gypsy chez Drosophila melanogaster.

ABSTRACT

Retroviruses are viruses that have the ability to synthesize a DNA copy from their RNA genome and to integrate it in the host genome. Sequencing of eukaryotic genomes has revealed the presence of many of these endogenous retrovirus sequences. The mechanisms by which these sequences colonize the genome are still unknown, and the endogenous retrovirus gypsy of Drosophila melanogaster (D. melanogaster) is a powerful experimental model deciphering this process. Gypsy is expressed in gonadic somatic cells and transferred into the oocyte. This critical step is the first one of the endogenization process. Moreover, gypsy has been shown to possess infectious properties, probably due to its envelope gene that is suspected to have been acquired from baculovirus. So far, gypsy is a unique model to understand endogenization of retroviruses.