Identification and genome characterization of a novel picornavirus from ducks in China

A novel picornavirus, referred to as Duck/FC22/China/2017, was isolated from breeding ducks in China and genetically characterized by conducting metagenomics studies. The complete genome consists of a single-stranded, positive-sense RNA made up of 7448 nucleotides (nt) and follows the common picornavirus genome layout: 5′ UTR-VP0-VP3-VP1-2A-2B-2C-3A-3B-3C-3D-3′ UTR. A typical type-IV internal ribosomal entry site and a conserved ‘barbell-like’ structure were identified in the 5′ UTR and 3′ UTR, respectively. The unique 6423-nt open reading frame was predicted to encode a 2141-amino-acid (aa) polyprotein precursor. A pairwise aa sequence identity comparison and phylogenetic analysis revealed that Duck/FC22/China/2017 is closely related to duck aalivirus, duck hepatitis A virus, turkey avisivirus , and red-crowned crane picornavirus.