Family: Kolmioviridae
Genus: Thurisazvirus
Distinguishing features
Tome’s spiny-rat virus 1 (TSRV1; previously referred to as RDeV) (Paraskevopoulou et al., 2020) was the first thurisazvirus to be classified (in the species Thurisazvirus myis), followed by bat deltavirus isolates LMA6, CAJ1, and AYA11 (Bergner et al., 2021) (members of the species Thurisazvirus desmodi). Thurisazviruses infect echimyid rodents and phyllostomid bats. TSRV1 replicates autonomously in vitro in HuH7 cells (Paraskevopoulou et al., 2020).
Virion
Virions are unknown.
Nucleic acid
Thurisazviruses have non-segmented, covalently-closed, circular negative-sense RNA (cccRNA) genomes of about 1.7 kb with 55.2% GC content (Paraskevopoulou et al., 2020).
Proteins
Thurisazviruses are predicted to express one delta antigen (DAg)-like protein of 196 amino-acid residues (Paraskevopoulou et al., 2020).
Biology
TSRV1 was discovered in Tome’s spiny-rats (echimyid Proechimys semispinosus (Tomes, 1860)) sampled in Panama (Paraskevopoulou et al., 2020). Bat deltavirus isolates LMA6, CAJ1, and AYA11 were discovered in phyllostomid bats in Peru (Bergner et al., 2021).
Species demarcation criteria
The genus currently includes two species. Members of the same species have a minimum of 80 % nt genome and 70 % S-DAg aa identity and form a monophyletic cluster in phylogenetic analyses.