Formation et évolution des rétrovirus endogènes

Endogenous retroviruses (ERV) are genetic parasites found in the genome of vertebrates. They are « remnants » of ancient infections by retroviruses that have integrated a copy of their genome in the germline of their host and have then been transmitted vertically to the progeny. A germline-integrated retrovirus can have multiple fates. Some elements can amplify in the host DNA, leading to the formation of multicopy families and the genomic invasion of entire populations. Some elements can gradually degenerate and remain only as fossil records in the host genome. Finally, some ERV can be conserved, either completely or partially, due to positive selection if their presence is beneficial for the fitness of their host. These different evolutions have led to the generation of diversified patterns of ERV in the different species of vertebrates.