Family: Phenuiviridae

Genus: Hudivirus

Distinguishing features

Húběi diptera virus 4 (HbDV4) is assigned to Hudivirus muscae, the only species in the genus. Hudivirus RNA was found by high-throughput sequencing of RNA from a fly. The hudivirus genome has four genes, encoding a large protein (L), two external glycoproteins (Gn and Gc) and a nucleocapsid protein (N). Based on well-supported Maximum Likelihood or Maximum Clade Credibility trees inferred from complete L protein sequences, viruses classified in the genus Hudivirus form a monophyletic cluster clearly distinguished from other phenuivirids (Shi et al., 2016).

Virion

Morphology

Virion morphology is unknown.

Nucleic acid

The hudivirus genome encompasses three segments of negative-sense RNA, namely L (6.9 kb), M (4.2 kb) and S (1.2 kb). Analysis of the terminal sequences has yet to be completed. All three genomic RNAs contain untranslated regions flanking a single ORF which, based on comparisons with other negative-sense RNA viruses, is predicted to be contained in the virus-complementary strand. In silico analysis of hudivirus putative ORF sequences suggests the hudivirus genome encodes three structural proteins: L with a predicted molecular mass of 255.2 kDa, a glycoprotein precursor (GP) of 140.2 kDa and N of 30.8 kDa, these proteins all sharing sequence homology and/or structural characteristics with the cognate proteins of other phenuivirids (Shi et al., 2016).

Genome organization and replication

The hudovirus genome consists of three negative-sense RNAs (Figure 1 Hudivirus). The hudovirus genome arrangement is similar to that of beidiviruses, citriciviruses, goukoviruses, hudiviruses, mobuviruses, phasiviruses, pidchoviruses, and tanzaviruses (Figure 2 Phenuivridae). The L, M, and S segments putatively encode L, a glycoprotein precursor (comprising Gn and Gc), and N, respectively. The Gn and Gc glycoproteins were earlier referred to as G1 and G2 based on apparent size following gel electrophoresis. The hudivirus genome does not encode either of the non-structural proteins NSs or NSm. Details of virus replication are unknown (Shi et al., 2016).

Figure 1 Hudivirus. Genome organization of a hudivirus. Coloured boxes depict ORFs that encode N, nucleocapsid protein; Gn and Gc, external glycoproteins; and L, large protein.

Biology

Hudiviruses have been detected in a pooled sample of flies (unidentified diptera) from Húběi (湖北省), China (Shi et al., 2016).

Species demarcation criteria

Not defined as the genus currently includes only a single species.

Related, unclassified viruses

Virus names and virus abbreviations are not official ICTV designations.