Partial characterization of a new type of bovine papilloma viruses

Papilloma virus isolates from 13 individual bovine cutaneous warts were characterized by monospecific rabbit antisera and were shown to fall into two groups without detectable crossreactivity when tested by immune electron microscopy or complement fixation. cRNA transcribed from representatives of both groups did not hybridize with DNA from heterologous isolates. The two types of BPV also differed in the electrophoretic mobility of their proteins and in the molecular weight of their DNA (4.5 × 10 6 and 4.9 × 10 6, respectively). One isolate with DNA of 4.9 × 10 6 MW and one isolate with DNA of 4.5 × 10 6 MW were analyzed by cleavage of their DNA with the restriction endonucleases BamHI, EcoRI, HindII, HindlH, and HaeHI and physical maps were established. The two genomes differed completely in their cleavage pattern. The HindII cleavage pattern demonstrated the identity of the large DNA isolate with BPV 2 of Lancaster et al. (personal communication). The other apparently new type of bovine papilloma virus, which was detected twice thus far, is tentatively designated as BPV 3.