Screening over 100 publicly available vertebrate genomes using an automatized BLAST approach we were able to confirm the presence of the already known endogenous lentiviruses in rabbit, domestic ferret, and gray mouse lemur. Not only did we confirm the previous findings, but we discovered a novel endogenous lentivirus in Malayan colugo, Galeopterus variegatus (denoted ELVgv).
This was the first report of an endogenous lentivirus in an Asian mammal, indicating a long-term presence of this retrovirus family in the Asian continent. Sequence analysis of three ELVgv integrations points to evolutionary age between 5 and 27 million years ago.
Galeopterus belongs to the mammalian order Dermoptera, which is close relative to the order primates. The only two extant genera in this order are Galeopterus and Cynocephalus.
We were able to identify the same lentivirus in Cynocephalus volans, confirming the exceptionally old age of infiltration of dermopteran lineage by ELVgv. Further studies of the ELVgv sequences present in Cynocephalus and Galeopterus propose questions concerning the evolution of the relationships between the Dermoptera and lentiviruses.
According to these analyses, ELVgv is probably the oldest lentivirus species described so far.