Cervus elaphus papillomavirus (CePV1): new insights on viral evolution in deer.

We identified a novel papillomavirus (CePV1) in a fibropapilloma of a 1.5 year old male red deer (Cervus elaphus) shot in the Italian Alps in Brescia province. PV particles were first observed by electron microscopy and PV DNA was then identified by PCR using degenerate primers. Subsequently we cloned the entire genome and determined its complete sequence. CePV1 genome is 8009 bp long and contains all 9 ORFs and the long untranslated regulatory region characteristic for Delta-papillomaviruses. Pairwise nucleotide alignments and phylogenetic analyses based on concatenated E1-E2-L1 ORFs allowed to determine the highest similarity with the Capreolus caprelus papillomavirus CcaPV1. The analysis of the host-parasite phylogenetic tree interactions suggest the co-divergence of CePV1 and C. elaphus while the identified topological incongruences leading us to speculate that CcaPV1 could eventually be the result of an earlier host switch event.