# Identification and characterization of a novel papillomavirus in thornback skate (Raja clavata)

## TL;DR

A new papillomavirus was discovered in thornback skates and found to be more closely related to amphibian viruses than fish viruses.

## Contribution

This is the first report of a complete papillomavirus genome identified in the thornback skate.

## Key findings

- The RclaPV1 genome is 5,539 bp long and encodes four core papillomavirus proteins.
- Phylogenetic analysis shows RclaPV1 is more closely related to amphibian papillomaviruses than fish ones.

## Abstract

Papillomaviruses are non-enveloped, double-stranded DNA viruses capable of infecting a wide range of vertebrates, from chondrichthyans to mammals. In this study, we report for the first time the identification and complete genome of a papillomavirus in the thornback skate (Raja clavata), named Raja clavata papillomavirus 1 (RclaPV1). The genomic sequence was determined using a metagenomic approach and subsequently confirmed by PCR. The RclaPV1 genome is 5,539 bp in length and displays the typical organization of papillomaviruses, encoding 4 core proteins on a single DNA strand: two early genes (E1 and E2) and two late genes (L1 and L2). Maximum likelihood phylogenetic analyses of the L1 and E1 genes indicate that RclaPV1 belongs to the Secondpapillomavirinae subfamily, clustering with fish and amphibian papillomaviruses and showing closer evolutionary relationships to amphibians than to fish.