Presence of papillomavirus-like DNA sequences in cutaneous fibropapillomas of the goat udder.

Papillomatous lesions were isolated from the mammary skin of goats and examined for evidence of papillomavirus (PV) infection by various criteria, including gross morphology, histology and DNA hybridization. Although some lesions showed gross papillomatous morphological and histological features similar to those caused by papillomavirus in other species, no viral particles were detected. Reverse slot hybridization revealed cross-hybridization between DNA extracted from goat mammary papillomas and human papillomaviruses (HPV). Southern blot, using ovine papillomavirus (OPV) and bovine papillomavirus type 5 (BPV 5) DNA probes under conditions of reduced stringency (Tm -40 degrees C), detected homologous sequences in 40% of the biopsies. DNA fragments corresponding probably to a monomeric form (7000-8000 bp) of an unknown papillomavirus genome were detected. This study provides evidence for the existence of papillomavirus-like sequences in caprine mammary papillomas and suggests that a papillomavirus is likely to be involved in the development of precancerous lesions of goat mammary skin.