Genome invasion: understanding the evolutionary and functional roles of mutation and recombination at the earliest stages of retroviral endogenization
Evolutionary Cell and Developmental Biology (Zoology)
Microbial Ecology and Applied Microbiology
Ecology and Biodiversity of Animals and Ecosystems, Organismic Interactions
Final Report Abstract
Screening of 278 bat and rodent taxa from the Australo-Papuan region (Australia and New Guinea) identified a novel retrovirus colonizing the germline of the New Guinea endemic rodent Melomys leucogaster. The virus was found in exactly the same location in the genome of a subset of different M. leucogaster individuals but absent from others, a telltale sign of germline colonization where the virus is transmitted vertically. The virus is a Gibbon ape leukemia virus, GALV (almost 99% identity with the woolly monkey virus which is a GALV). The virus has been named complete melomys woolly monkey virus (cMWMV), and unlike other viruses identified in the germline of rodents in the region, it retains all viral functions as confirmed by protein modelling and cell culture experiments. The only other model for determining how the 10% of the vertebrate genome that is retroviral is formed has to this point been the koala retrovirus, KoRV. The cMWMV represents a second model in a small bodied mammal. In addition to frequent germline colonization events occurring in the Australo-Papuan region in Melomys species, we identified selection on the ZAP (zinc-finger CCCH-type antiviral protein 1) gene, of Melomys leucogaster above the elevated levels of selection generally observed in rodents. We speculate that this may be a consequence of the intense pressure exerted by GALV-KoRV like viruses circulating in rodents and bats in the region. The Australo-Papuan region is likely a hotspot for viruses that are recently or currently colonizing vertebrate genomes opening a window into the process.
