Family: Picornaviridae

Genus: Dicipivirus

 

Distinguishing features

In contrast to other picornaviruses, the genome layout of dicipiviruses exhibits two ORFs separated by an intergenic region (IGR) that functions as an IRES to translate the second ORF. The IGR-IRES shows no similarity to the equivalent region in members of the Dicistroviridae

Virion

Morphology

No details are available on the morphology of virions. 

Nucleic acid

Genome (Woo et al., 2012, Reuter et al., 2018): 8,785–8,838 nt (5′-UTR: 776–982 nt; ORF1: 2,535–2,757 nt; IGR: 588–591 nt; ORF2: 4,221–4,581 nt; 3′-UTR: 133–549 nt). The 5′-UTR harbours a type II IRES whereas the IGR-IRES has similarities to the type I IRES of enteroviruses. The location of the cre has not been identified. 

Genome organization and replication

Genome layout:

VPg+5′-UTRIRES-II-[1A-1B-1C-1D]-IGRIRES-I[2A-2B-2C/3A-3B-3C-3D]-3′-UTR-poly(A)

The predicted polyproteins are of 845–919 aa (P1) and 1,407–1,527 aa (P2-P3), respectively. There is no L protein. P1 comprises four capsid proteins (1A–1D); 1A lacks a myristoylation signal. The function of the 2A protein is unknown. 

Biology

No virus has been isolated. Viral RNA was detected in the faeces of diseased and healthy dogs and in faecal samples, blood and various tissues of northern white-breasted hedgehogs (Erinaceus roumanicus). 

Derivation of names

Cadicivirus A-: from canine dicistronic

Dicipivirus: from dicistronic picorna

Species demarcation criteria

Based on available sequence data, preliminary species demarcation criteria were defined. Members of a species of genus Dicipivirus:

  • share a common, dicistronic genome organization
  • share less than 30% aa diversity in the P1 (orf 1)
  • share less than 30% aa diversity in the non-structural proteins 2C + 3CD