Molecular cloning of bovine papillomavirus genomes and comparison of their sequence homologies by heteroduplex mapping.

The genomic DNAs of bovine papillomavirus (BPV) type 1, type 2 and type 4 were cloned in pAT153. BPV1 and BPV2 genomes were cloned using the single HindIII sites of the vector and virus DNAs, and BPV4 was cloned using the single BamHI sites. The orientation of the recombinant DNAs was established by restriction enzyme digestion, hybridization and heteroduplex analysis. The results showed that: (i) BPV1 and BPV2 DNAs are in register and are broadly homologous throughout most of their length when aligned at their single HindIII sites; (ii) depending on the degree of hybridization stringency used, the two DNAs show one major region and several minor regions of partial homology, mainly residing in the segment of the genomes believed to contain the structural genes; (iii) BPV4 DNA shares no homology with either BPV1 or BPV2 DNA.