Genus: Peropuvirus


Genus: Peropuvirus

Distinguishing features

The genus Peropuvirus includes a single species represented by Pteromalus puparum negative-strand RNA virus 1 (PpNSRV1) (Wang et al., 2017). The PpNSRV1 genome is 13.8% identical to that of soybean cyst nematode virus 1 (SbCNV1, genus Socyvirus), 12.3 % identical to that of Nyamanini virus (NYMV, genus Nyavirus), 12.1% identical to that of Midway virus (MIDWV, genus Nyavirus), and 10.9% identical to that of Sierra Nevada virus (SNVV, genus Nyavirus). This is lower than the 17% identity between the genomes of members of the two other nyamiviral genera (Nyavirus and Socyvirus).

Virion

Morphology

Spherically shaped virions (62.5–100 nm in diameter) were present in follicular cells of the ovaries of infected wasps. Similarly, virion-like particles (70–100 nm in diameter) stacked in intracellular vesicles were observed in cells of the digestive tract. The spherical PpNSRV1 particle shape is similar to particles produced by nyaviruses (Wang et al., 2017).

Nucleic acid

Unsegmented negative-sense single stranded RNA genome of 12.2 kb with a G+C content of 46%. 

Proteins

The amino acid sequence of the PpNSRV1 ORF V protein is similar to that of the RNA-dependent RNA polymerase (RdRP) of MIDWV. Moreover, the ORF IV protein contains 7 potential O-linked and 4 potential N-linked glycosylation sites and 29 potential phosphorylation sites, suggesting that ORF IV may encode the viral glycoprotein G. The ORF I protein is predicted to have 37 potential phosphorylation sites, whereas the ORF II protein has 9 potential phosphorylation sites. The ORF III protein contains 37 potential O-linked glycosylation sites. ORF III may encode a glycosylated matrix protein M and ORF I may encode the viral nucleoprotein N. Based on the conserved genomic organization of mononegaviruses, ORF II is suggested to encode a phosphoprotein (P) (Wang et al., 2017).

Genome organization and replication

The PpNSRV1 genome contains five large, independently-transcribed, non-overlapping ORFs (Figure 2.Nyamiviridae) flanked by 3' leader and 5' trailer regions whose terminal nucleotides do not exhibit obvious complementarity. Typical conserved transcription initiation and termination motifs are identified upstream and downstream, respectively, of each putative ORF.

Biology

PpNSRV1 was originally isolated from a laboratory parasitoid strain of the pteromalid wasp Pteromalus puparum. PpNSRV1 is present in various tissues and life stages of the parasitoid, and is transmitted vertically through females and males. PpNSRV1 increases adult longevity and impairs several fitness parameters of the wasp but has no influence on successful parasitism. PpNSRV1 moderates the offspring sex ratio by decreasing female offspring numbers (Wang et al., 2017).

Species demarcation criteria

Not applicable

Member species

SpeciesVirus name(s)Exemplar isolateExemplar accession numberExemplar RefSeq numberAvailable sequenceOther isolatesOther isolate accession numbersVirus abbreviationIsolate abbreviation
Barnacle peropuvirusBěihǎi barnacle virus 8BHTH14652KX884410NC_032430Complete coding genomeBhBV-8
Beihai peropuvirusBěihǎi rhabdo-like virus 1BHTSS15727KX884412NC_032555Complete coding genomeBhRLV-1
Hubei peropuvirusHúběi rhabdo-like virus 6QTM24798KX884421Complete coding genomeHbRLV-6
Odonate peropuvirusHúběi rhabdo-like virus 8QTM19395KX884420Complete coding genomeHbRLV-8
Pillworm peropuvirusHúběi rhabdo-like virus 5WHSFII19440KX884446Complete coding genomeHbRLV-5
Pteromalus puparum peropuvirusPteromalus puparum negative-strand RNA virus 11KX431032NC_038269Complete genomePpNSRV-1
Woodlouse peropuvirusBěihǎi rhabdo-like virus 2BHTSS7258KX884413NC_032558Complete coding genomeBhRLV-2

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

Derivation of names

Genus: acronym of Pteromalus puparum, Peropu- and -virus. Species: named after the host species.