Discovery of novel fish papillomaviruses: From the Antarctic to the commercial fish market

Fish papillomaviruses form a newly discovered group broadly recognized as the Secondpapillomavirinae sub-family. This study expands the documented genomes of the fish papillomaviruses from six to 16, including one from the Antarctic emerald notothen, seven from commercial market fishes, one from data mining of sea bream sequence data, and one from a western gull cloacal swab that is likely diet derived. The genomes of sec-ondpapillomaviruses are ~6 kilobasepairs (kb), which is substantially smaller than the ~8 kb of terrestrial vertebrate papillomaviruses. Each genome encodes a clear homolog of the four canonical papillomavirus genes, E1, E2, L1, and L2. In addition, we identified open reading frames (ORFs) with short linear peptide motifs reminiscent of E6/E7 oncoproteins. Fish papillomaviruses are extremely diverse and phylogenetically distant from other papillomaviruses suggesting a model in which terrestrial vertebrate-infecting papillomaviruses arose after an evolutionary bottleneck event, possibly during the water-to-land transition.

Automated summary

This study expands the known genomes of fish papillomaviruses and reveals their genetic distance from other papillomaviruses, suggesting a bottleneck event in the evolution of papillomaviruses infecting terrestrial vertebrates.