Simultaneous presence of bovine papillomavirus and bovine leukemia virus in different bovine tissues: in situ hybridization and cytogenetic analysis.

Bovine papillomavirus (BPV) DNA sequences were detected in different tissues, in addition to epithelium. Cytogenetic abnormalities were observed in blood lymphocytes. The presence of more than one virus in a single tissue is a difficult aspect to evaluate, especially when the DNA sequences are detected in tissues that are not specifically targeted by the virus. BPV and bovine leukemia virus (BLV) are clastogenic, causing chromosome aberrations in peripheral blood lymphocytes. In the present study, we investigated the simultaneous presence of DNA sequences of both viruses and the possibility of vertical transmission and compared the types of chromosome aberrations related to viral action. BPV 1, 2, and 4 DNA sequences were found in three females of the herd and in their offspring. BLV DNA sequences were not detected in their progeny. A newborn calf that was negative for BLV infection showed specific chromosome rearrangements possibly related to the effect of infection with BPV.