Genomic characterisation of Felis catus papillomavirus 4, a novel papillomavirus detected in the oral cavity of a domestic cat.

Three papillomaviruses (PVs) from the domestic cat have been fully sequenced so far including Felis domesticus PV-1 (FdPV-1), FdPV-2, and a recently described Felis catus PV-3 (FcaPV-4). In the current article, we describe the full genomic sequence of a fourth PV from the domestic cat. This PV was amplified from the oral cavity of a cat with severe gingivitis. However, the aetiological involvement of FcaPV-4 in development of lesions observed in this cat remains uncertain. The complete genome of the novel virus comprised 7,616 bp and was predicted to encode five early (E1, E2, E4, E6 and E7) and two late (L1 and L2) genes, with the organisation typical for PVs. The L1 showed 65.1 % nucleotide sequence identity to L1 of FcaPV-3 and approximately 60 % identity to L1 of canine tau-papillomaviruses CPV-2 and CPV-7. The novel virus clustered with FcaPV-3, CPV-2 and CPV-7 on a phylogenetic tree constructed from a concatenated alignment of 3,013 bp from E1, E2, L1 and L2. Based on the genomic and phylogenetic data, we propose that the novel virus is classified as a distinct species within the same genus as FcaPV-3. We also propose that both viruses are classified within the genus Taupapillomavirus, although this classification may need to be re-visited after more tau-PV genomes become available.