Characterization of cellular sequences flanking an integrated bovine leukemia virus genome

We cloned a 20.2-kilobase fragment, including the unique proviral integration site, from the tumor tissue DNA of a bovine leukemia virus-induced lymphoma (tumor 1351). This clone contained 5.5 kilobases of flanking sequences at either side of the full-length integrated viral genome. Hybridization analysis of both 3' and 5' cellular flanking regions provided no evidence for rearrangements at this locus in other tumors, RNA transcription from either flanking region, or homology to eight known onc genes.