Family: Picornaviridae

Genus: Limnipivirus

Distinguishing features

The genus is distinguished on the basis of genetic characters. 

Virion

Morphology

No surface morphology of the icosahedral capsid is visible by EM. 

Nucleic acid

Genome (Lange et al., 2014, Barbknecht et al., 2014, Phelps et al., 2014): c. 7,700–8,050 nt (5′-UTR: >501–712 nt; ORF: 6,810–7,011 nt; 3′-UTR: 312–363 nt). The 5′-UTR contains a type IV IRES. 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^npgp/-2B-2C/3A-3B-3C-3D]-3′-UTR-poly(A)

The deduced polyprotein is of 2,337 aa. There is no L protein. 1AB remains uncleaved and has an N-terminal myristoylation signal. There are two 2A proteins with NPG↓P motifs. 

Biology

Known limnipiviruses infect freshwater fishes. The virus can be grown in various fish cell lines. Experimental infection of bluegills with bluegill picornavirus induces morbidity (inflammation and redness at the base of fins, exophthalmia, abdomen distension, internal hemorrhaging and ascites) and mortality. 

Derivation of names

Limnipivirus: from Greek limne, 'lake' and picornavirus. 

Species demarcation criteria

Members of a species of the genus Limnipivirus share a common genome organization. 

The divergence (number of differences per site between sequences) between members of different Limnipivirus species ranges from 0.3–0.43 for P1 and 0.49–0.57 for 3CD. Sequence data indicate a second genetic type of Limnipivirus B. 

Related, unclassified viruses

Virus names and virus abbreviations are not official ICTV designations.