Genome characterization of a novel chicken picornavirus distantly related to the members of genus Avihepatovirus with a single 2A protein and a megrivirus-like 3′ UTR

The members of the genus Avihepatovirus and related picornaviruses ("Aalivius") of ducks, turkey and chickens possess identical 2A peptide composition including three functionally unrelated 2A peptides which is a characteristic genome feature of these monophyletic avian picornaviruses. The complete genome of a novel picornavirus provisionally named Orivirus A1 (KM203656) from a cloacal sample of a 4-week-old diarrheic chicken (Gallus gallus domesticus) distantly related to members of genus Avihepatovirus was characterized. The study strain contains a type-II-like IRES, a single 2A protein of unknown function unrelated to the 2A proteins of avihepatoviruses and a long 3' untranslated region (UTR) with multiple repeated sequence motifs followed by an AUG-rich region. The repeated sequences of the 3' UTR show significant identity to the "Unit A" sequences of the phylogenetically distant megriviruses. The presence of a novel single 2A and the megrivirus-like "Unit A" motifs suggest multiple recombination events in the evolution of this novel picornavirus. (C) 2014 Elsevier B.V. All rights reserved.