Distinguishing features

The genus is distinguished on the basis of genetic characters.

Virion

Morphology

No details are available on the morphology of virions.

Nucleic acid

Genome (Woo et al., 2010, Pankovics et al., 2018): up to 9,130 nt (5′-UTR: c. 807 nt; ORF: 7,287–8,004 nt; 3′-UTR: 319–334 nt). The location of the cre has not been identified. 

Genome organization and replication

Genome layout:

VPg+5′-UTR^IRES-[L-1AB-1C-1D/2A^H-box/NC-2B-2C/3A-3B-3C-3D]-3′-UTR-poly(A)

The deduced polyprotein is of 2,428 aa (passerivirus A1) and 2,668 aa (passerivirus B1), respectively. There is a long L protein of unknown function. The 1AB protein (with myristoylation signal) remains uncleaved. The 2A protein has an H-box/NC sequence motif.

Biology

No virus has been isolated. Viral RNA was detected in faeces of thrushes (Turdus hortulorum, T. merula, T. pallidus) and diseased home-reared estrildid finches (Uraeginthus sp.).

Derivation of names

Passerivirus: from the order Passeriformes (perching birds), from Latin passer, 'sparrow'

Species demarcation criteria

Members of a species of genus Passerivirus:

• share a common genome organization
• are less than 30% divergent in the polyprotein aa sequence
• are less than 30% divergent in the P1 aa sequence
• are less than 25% divergent in the 2C + 3CD aa sequence

Member species

Virus names, the choice of exemplar isolates, and virus abbreviations, are not official ICTV designations.