Cytogenetic studies in peripheral blood of bovines afflicted by papillomatosis.

Ten types of bovine papillomavirus (BPV) have been described and there are reports of viral transmission via blood. The presence of viral DNA in lymphocytes was described to be associated with chromosome instability in these cells. This study presents an evaluation of chromosome instability in short-term peripheral lymphocyte cultures from cows presenting skin papillomatosis, compared with asymptomatic infected animals and non-infected healthy bovines. In a total of 2203 cells, 918 (42%) showed at least one chromosome aberration: 42.7 (± 7.8) in animals with papillomatosis (BPV + W), 40.2 (± 11) in asymptomatic animals (BPV-W) and 4 (± 2) in control animals. Significant differences were found between the infected group (with or without symptoms) and the control group (P < 0.0001). The increased frequencies of chromosome aberrations suggest an interaction between the virus and host cell chromatin.