xi river virus xi river virus xi river virus (xrv) is a putative novel bat virus in the genus orthoreovirus isolated from fruit bats in guangdong province in southern china. it is the first bat reovirus isolated in china. xi river virus virus classification (unranked): virus realm: riboviria kingdom: orthornavirae phylum: duplornaviricota class: resentoviricetes order: reovirales family: reoviridae genus: orthoreovirus species: incertae sedis virus: xi river virus virology genome only a partial sequence of xrv was isolated from the fruit bat, but based on its open reading frame it was identified as a reovirus. xrv has the same morphology and high sequence identity as nelson bay virus (nbv), and a 10-segmented double-stranded rna genome, as well as high sequence identity to nbv members. reoviruses are non-enveloped, double-stranded rna viruses. they have an icosahedral capsid (t-13) composed of an outer and inner protein shell. the genome contains 10–12 segments grouped into three categories by size: l (large), m (medium) and s (small). segments range from ~ 3.9 kbp – 1kbp and each segment encodes 1–3 proteins. reoviridae proteins are denoted by the greek character corresponding to the segment it was translated from (the l segment encodes for λ proteins, the m segment encodes for μ proteins and the s segment encodes for σ proteins).