Family: Picornaviridae

Genus: Pasivirus

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 (Sauvage et al., 2012, Yu et al., 2013, Boros et al., 2015a): c. 6,938 nt (5′-UTR: c. 420 nt; ORF: c. 6,402 nt; 3′-UTR: 136 nt). The location of the cre has not been identified. 

Genome organization and replication

Genome layout:

VPg+5′-UTR^IRES-IV-[1AB-1C-1D-2A1^npgp/-2A2-2B-2C/3A-3B-3C-3D]-3′-UTR-poly(A)

The deduced polyprotein is of c. 2,133 aa. There is no L protein. The 1AB protein remains uncleaved. The 2A1 protein has an NPG↓P sequence motif; the function of 2A2 is unknown. The 3D^pol of all known pasiviruses has the motif ASG rather than PSG. 

Biology

The natural host is likely the domestic pig (Sus scrofa). No virus has been isolated. Viral RNA has been detected in faeces of pigs. Four types are distinguished by means of phylogenetic analysis. 

Derivation of names

Pasivirus: from parecho sister-clade

Species demarcation criteria

There is only a single species in the genus.