PHYLOGENETIC RELATIONSHIP OF THE COMPLETE RAUSCHER MURINE LEUKEMIA-VIRUS GENOME WITH OTHER MURINE LEUKEMIA-VIRUS GENOMES

We report the complete nucleotide sequence of the genome of Rauscher m urine leukemia virus (R-MuLV), the replication-competent helper virus present in the Rauscher virus complex, and its phylogenetic relationsh ip with other murine leukemia virus genomes. An overall sequence ident ity of 97.6% was found between R-MuLV and the Friend helper virus (F-M uLV), and the two viruses were closely related on the phylogenetic tre es constructed from either gag, pol, or env sequences. Moloney murine leukemia virus (Mo-MuLV) was the next closest relative to R-MuLV and F -MuLV on all trees, followed by Akv and radiation leukemia virus (RadL V). The most distantly related helper virus was Hortulanus murine leuk emia virus (Ho-MuLV). Interestingly, Cas-Br-E branched with Mo-MuLV on the gag and pol trees, whereas on the env tree, it revealed the highe st degree of relatedness to Ho-MuLV, possibly due to an ancient recomb ination with an Ho-MuLV ancestor. In summary, a phylogenetic analysis involving various MuLVs has been performed, in which the postulated cl ose relationship between R-MuLV and F-MuLV has been confirmed, consist ent with the pathobiology of the two viruses. (C) 1997 Academic Press.