Discovery of a new endogenous type C retrovirus (FcEV) in cats: Evidence for RD-114 being an FcEV(Gag-Pol)/baboon endogenous virus BaEVEnv recombinant

Analysis of a cat genomic DNA library showed that cats harbor a previously unrecognized endogenous type C retrovirus, whose env gene has homology to t he murine Fv-4 resistance gene. This unique retrovirus, designated FcEV (Fe lis catus endogenous retrovirus), has a type C pol gene, closely related to the primate Papio cynocephalus endogenous virus (PcEV) pol, not overlappin g the env gene, unlike in other type C retroviruses, and is presumably pres ent in a higher copy number than RD-114, Phylogenetic analysis of FcEV and RD-114 fragments amplified from cat species and comparison with baboon endo genous virus (BaEV) fragments from monkeys suggested that RD-114 does not r epresent the eat strain of BaEV but is actually a new recombinant between F cEV type C genes and the env gene of BaEV, Although BaEV did appear to have infected an ancestor of the domestic eat lineage, it was a de novo recombi nant that made its way into the cat germ line.