A highly divergent picornavirus infecting the gut epithelia of zebrafish (Danio rerio) in research institutions world-wide

Abstract

Zebrafish have been extensively used as a model system for research in vertebrate development and pathogen-host interactions. We describe the complete genome of a novel picornavirus identified during a viral metagenomics analysis of zebrafish gut tissue. The closest relatives of this virus showed identity of [≤]19.8% in their P1 capsids and [≤]35.4% in their RdRp qualifying zebrafish picornavirus 1 (ZfPV1) as member of a novel genus with a proposed name of Cyprivirus. RT-PCR testing of zebrafish from 41 institutions from North America, Europe, and Asia showed ZfPV1 to be highly prevalent world-wide. In situ hybridization of whole zebrafish showed viral RNA was restricted to a subset of enterocytes and cells in the subjacent lamina propria of the intestine and the intestinal mucosa. This naturally occurring and apparently asymptomatic infection (in wild type zebrafish lineage AB) provides a natural infection system to study picornavirus-host interactions in an advanced vertebrate model organism. Whether ZfPV1 infection affects any immunological, developmental or other biological processes in wild type or mutant zebrafish lineages remains to be determined.