Family: Peribunyaviridae
Genus: Gryffinivirus
Distinguishing features
The genus Gryffinivirus includes two species. Hedwig virus (HEDV, species Gryffinivirus hedwigae), was identified in 2018 from a captive snowy owl in Germany (Santos et al., 2021). Unlike orthobunyaviruses and pacuviruses, gryffiniviruses do not contain the conserved Gn C-terminus (VAKI306), in this respect only comparable to herbeviruses and shangaviruses. Additionally, the Gc C-terminal protein contains a 26–35 amino acid insertion. Phylogenetic inference of Hedwig virus, Asum virus and Udune virus, shows a distinct new branch basal to the genus Pacuvirus (Batson et al., 2021, Santos et al., 2021).
Virion
Nucleic acid
Gryffinivirus RNA displays the peribunyavirus-typical tri-partite, negative-sense genome organization. The terminal nucleotides of each segment (S, M, and L) remain to be determined.
Carbohydrates
The gryffinivirus glycoprotein is predicted to have 9 N-glycosylation sites, three on Gn and six on Gc (Santos et al., 2021).
Genome organization and replication
The tri-partite gryffinivirus genome is similar to those of other peribunyaviruses. The S (small), M (medium), and L (large) segments encode a nucleoprotein (N), glycogproteins (Gn, Gc) and large protein (L), respectively (Figure 1 Gryffinivirus). The L protein includes an endonuclease in the N-terminus and six conserved RNA-directed RNA polymerase motifs, including pre-A and motifs A–E, in the central region. The gryffinivirus genome encodes non-structural proteins NSs or NSm, similar to those encoded by orthobunyaviruses (Santos et al., 2021). Details of virus replication are unknown.
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| Figure 1 Gryffinivirus. Gryffinivirus coding strategy. vcRNAs are depicted in 3′→5′ direction and mRNAs are depicted in a 5′→3′ direction. Coloured boxes on the mRNAs depict ORFs that encode the N, nucleocapsid protein; Gn and Gc, external glycoproteins; L, large protein. |
Biology
Three gryffiniviruses have been identified; HEDV was identified in 2018 from a captive snowy owl in Germany, Asum virus (also a member of the species Gryffinivirus hedwigae) was identified in Culex pipiens in France in 2015, while Udune virus (species Gryffinivirus alamedaense) was identified in Culex pipiens in Alameda County, California, USA. There is evidence that gryffiniviruses may be arboviruses. Details of the transmission cycle and diseases remain unknown (Santos et al., 2021).
Species demarcation criteria
Species within the genus Gryffinivirus can be defined by:
- Less than 90% identity in the complete amino acid sequence of the L protein