Family: Phenuiviridae
Genus: Beidivirus
Distinguishing features
The genus Beidivirus includes four virus species. Beidiviruses have been identified in flies and a common bluetail damselfly. The beidivirus genome has three genes, encoding a large protein (L), a glycoprotein precursor (GP) 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 Beidivirus form a monophyletic cluster clearly distinguished from other phenuivirids. There currently is no cultured beidivirus isolate (Shi et al., 2016).
Virion
Morphology
Virion morphology is unknown.
Nucleic acid
The beidivirus genome encompasses three segments of negative-sense RNA: L (6.6–6.8 kb), M (3.6–4.0 kb), and S (1.4–1.8 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 beidivirus putative ORF sequences suggests that the beidivirus genome encodes three structural proteins: L with a predicted molecular mass of 244.5–257.9 kDa, a glycoprotein precursor (GP) of 129.5–143.0 kDa, and N of 32.4–59.1 kDa. These proteins share sequence homology and/or structural characteristics with the cognate proteins of other phenuivirids (Table 3 Phenuiviridae) (Shi et al., 2016).
Genome organization and replication
The beidivirus genome consists of three negative-sense RNAs (Figure 1 Beidivirus). The beidivirus genome arrangement is similar to that of citriciviruses, goukoviruses, hudiviruses, hudoviruses, mobuviruses, phasiviruses, pidchoviruses, and tanzaviruses (Figure 2 Phenuivridae). The L, M and S segments putatively encode L, a glycoprotein precursor and N, respectively. While the beidivirus GP harbors the phlebovirus glycoprotein G2 fusion domain, the GP lacks the phlebovirus glycoprotein G1 and the C-terminal Ig-like domains, its potential functional congruence with GPs of other bunyavirals remains to be elucidated. The beidivirus genome does not encode either of the non-structural proteins NSm or NSs. Details of virus replication are unknown (Shi et al., 2016).
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| Figure 1 Beidivirus. Genome organization of a beidivirus. Coloured boxes depict ORFs that encode N, nucleocapsid protein; GP, glycoprotein precursor; and L, large protein. |
Biology
Beidiviruses have been detected by high-throughput sequencing of RNAs from the pools of flies [Liriomyza huidobrensis (Blanchard, 1926) and unidentified Drosophila] and a common bluetail [Ischnura senegalensis (Rambur, 1842)]) in China, South Korea, and UK.
Species demarcation criteria
The criteria demarcating species in the genus are:
• Less than 95% identity in the amino acid sequence of the L protein.