Evolutionary conservation and chromosomal localization of flvi-1.

A locus in feline DNA, termed flvi-1, has been identified as harboring retroviral integrations commonly found in natural feline lymphomas induced by infection with feline leukemia virus (FeLV). Southern blot analysis of human and murine DNA using restriction fragments representing flvi-1 demonstrates its phylogenetic conservation among mammals, flvi-1 is localized to murine chromosome 2, proximal portion of band E, by in situ hybridization to metaphase chromosomes. This position is adjacent to that of another putative proto-oncogene, sfpi-1, although probes representing flvi-1 and sfpi-1 do not cross-hybridize. The repeated implication of flvi-1 in natural feline leukemogenesis, its evolutionary conservation and its chromosomal position support the hypothesis that flvi-1 may represent a previously unidentified protooncogene.