Family: Picornaviridae
Genus: Anativirus
Distinguishing features
The genus is distinguished on the basis of genetic characters. The known anativiruses lack a functional 2A protein.
Virion
Morphology
No details are available on the morphology of the virions.
Nucleic acid
Genome: (Tseng and Tsai 2007, Pankovics et al., 2012, Boros et al., 2016) and (J.G. Morgan, S. Bullman, B. Lucey, unpublished) 8,159–8,226 nt (5′-UTR: up to 425 nt; ORF: 7,446–7,563 nt; 3′-UTR: 219–238 nt). The location of the cre has not been identified.
Genome organization and replication
Genome layout:
VPg+5′-UTRIRES-[Lpro-1A-1B-1C-1D/2A-2B-2C/3A-3B-3C-3D]-3′-UTR-poly(A)
The deduced polyprotein is of 2,482–2,521 amino acids. The predicted leader polypeptide of duck picornavirus is the longest known at 451 aa and suspected to be a trypsin-like protease. The L/VP0 cleavage and presence of a potential myristoylation site on VP0 is predicted for duck picornavirus (kQ/GqvqS). The 2A region is largely deleted with a residual 6 aa remaining.
Biology
Duck picornavirus was isolated from intestinal tracts of duckling with duck virus hepatitis (Tseng and Tsai 2007). The virus, however, could not produce hemorrhagic lesions in the liver and causes a less fatal disease. RNA of members of Anativirus B has been detected in faecal samples of quails and in cloacal swabs and caecum samples of chickens. Two types of Anativirus B are distinguished namely phacovirus and chicken picornavirus (both anativirus B1) and quail picornavirus (anativirus B2).
Derivation of names
Anativirus: from Anatidae, the family of birds that includes ducks, geese and swans.
Species demarcation criteria
Members of a species of the genus Anativirus:
- are less than 30% divergent in polyprotein aa sequence
- are less than 40% divergent in P1 aa sequence
- are less than 35% divergent in 2C+3CD aa sequence
- share a common genome organization