[2] Double-stranded RNA viruses are classified into two phyla, Duplornaviricota and Pisuviricota (specifically class Duplopiviricetes), in the kingdom Orthornavirae and realm Riboviria.

[3] Virus group members vary widely in host range (animals, plants, fungi, and bacteria), genome segment number (one to twelve), and virion organization (T-number, capsid layers, or turrets).

Based on phylogenetic analysis of RdRp, the two clades do not share a common dsRNA ancestor but are instead separately descended from different positive-sense, single-stranded RNA viruses.

The phylum is divided into three classes: Chrymotiviricetes, which primarily contains fungal and protozoan viruses, Resentoviricetes, which contains reoviruses, and Vidaverviricetes, which contains cystoviruses.

Like other members of the family, the reoviruses are non-enveloped and characterized by concentric capsid shells that encapsidate a segmented dsRNA genome.

CPV exhibits striking capsid stability and is fully capable of endogenous RNA transcription and processing.

The CPV turret protein contains two methylase domains with a highly conserved helix-pair/β-sheet/helix-pair sandwich fold but lacks the β-barrel flap present in orthoreovirus λ2.

[9] Some pathogenic rotovirus lineages that infect humans appear to have evolved through multiple interspecies reassortment events.

[9] Intragenic recombination may occur when the VP1 RNA-dependent RNA polymerase replicates part of one template strand before switching to another.

[9] The members of genus Orbivirus within the Reoviridae family are arthropod borne viruses and are responsible for high morbidity and mortality in ruminants.

BTV, like other members of the family, is a complex non-enveloped virus with seven structural proteins and a RNA genome consisting of 10 variously sized dsRNA segments.

One member of this family, Rice Dwarf Virus (RDV), has been extensively studied by electron cryomicroscopy and x-ray crystallography.

IBDV shares functional strategies and structural features with many other icosahedral dsRNA viruses, except that it lacks the T = 1 (or pseudo T = 2) core common to the Reoviridae, Cystoviridae, and Totiviridae.

The T = 13 shell of the IBDV capsid is formed by trimers of VP2, a protein generated by removal of the C-terminal domain from its precursor, pVP2.

[16] Since cells do not produce double-stranded RNA during normal nucleic acid metabolism, natural selection has favored the evolution of enzymes that destroy dsRNA on contact.