Physicochemical and physical properties
The Wǔhàn sharpbelly bornavirus (WhSBV) genome consists of negative-sense non-segmented single-stranded RNA (about 8.99 kb).
Based on sequence comparisons, cultervirus genomes encode homologs of orthobornavirus proteins N, X, P, M, G, and L (see Table 1.Orthobornavirus in the Orthobornavirus genus section).
Genome organization and replication
The cultervirus genome organization resembles that of carboviruses by having the gene order 3′-N-X/P-G-M-L-5′ (Shi et al., 2018). The replication of culterviruses has not yet been described.
The presumed reservoir hosts of culterviruses are fish. WhSBV was sequenced from a specimen of a sharpbelly (Actinopterygii: Cyprinidae: Hemiculter leucisculus (Basilewsky, 1855)) in Wǔhàn, Húběi Province, China (Shi et al., 2018), whereas the sequence of Murray-Darling carp bornavirus (MDCBV) originates from a common carp (Actinopterygii: Cyprinidae: Cyprinus carpio [Linnaeus, 1758]) from the Murray-Darling basin, Australia (Costa et al., 2021).
Species demarcation criteria
The genus only includes a single species.