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).

Derivation of names

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

Member Species

SpeciesVirus name(s)Exemplar isolateExemplar accession numberExemplar RefSeq numberAvailable sequenceOther isolatesOther isolate accession numbersVirus abbreviationIsolate abbreviation
Pteromalus puparum peropuvirusPteromalus puparum negative-strand RNA virus 1HZKX431032Complete genomePpNSRV-1

Virus names, the choice of exemplar isolates, and virus abbreviations, are not official ICTV designations.
Download GenBank/EMBL query for sequences listed in the table here.