Genetic characterization of a novel bovine papillomavirus member of the Deltapapillomavirus genus.

This report describes the complete genomic sequence and taxonomic position of BPV type 13. The BPV13 genome was amplified using the multiply primed rolling-circle amplification technique and long-template PCR employing two specific primers. The two long PCR fragments obtained were cloned and sequenced via primer walking. The complete genomic sequence of the BPV13 contains 7961 bp encoding eight proteins, E1, E2, E4, E5, E6, E7, L1, and L2. Similarly to the E5 gene in BPVs 1 and 2, the putative BPV13 E5 ORF encodes a small transforming protein that contains a hydrophobic transmembrane domain. Meanwhile, the retinoblastoma tumor suppressor-binding domain is absent in the putative BPV13 E7 protein. The presence of these two specific molecular features has been recognized as a distinct marker for the development of fibropapilloma in artiodactyl PV-induced lesions. The phylogenetic analysis demonstrated that BPV13 is a new member of the Deltapapillomavirus genus, to be classified as the third representative of the Delta 4 species. The characterization of the genomic sequence of this novel PV will aid in the interpretation of the pathologies described to be related to this virus and provide support for the development of diagnostic tools for epidemiological surveillance of BPV13 in its potential natural hosts.