Endogenous Lentiviral Elements in the Weasel Family (Mustelidae)

Endogenous retroviruses provide molecular fossils for studying the ancient evolutionary history of retroviruses. Here, we report our independent discovery and analysis of endogenous lentiviral insertions (Mustelidae endogenous lentivirus [MELV]) within the genomes of weasel family (Mustelidae). Genome-scale screening identified MELV elements in the domestic ferret (Mustela putorius furo) genome (MELVmpf). MELVmpf exhibits a typical lentiviral genomic organization. Phylogenetic analyses position MELVmpf basal to either primate lentiviruses or feline immunodeficiency virus. Moreover, we verified the presence of MELV insertions in the genomes of several species of the Lutrinae and Mustelinae subfamilies but not the Martinae subfamily, suggesting that the invasion of MELV into the Mustelidae genomes likely took place between 8.8 and 11.8 Ma. The discovery of MELV in weasel genomes extends the host range of lentiviruses to the Caniformia (order Carnivora) and provides important insights into the prehistoric diversity of lentiviruses.