Comparison of the amino acid sequences of RNA-dependent RNA polymerases of cypoviruses in the family Reoviridae.

The nucleotide sequences of the genome segment S2 of Bombyx mori cypovirus 1, S2 of Lymantria dispar cypovirus 1, S1 of Lymantria dispar cypovirus 14 and S1 of a proposed new electropherotype of Trichoplusia ni cypovirus 15 were determined. These segments encoded putative RNA-dependent RNA polymerases (RDRPs). The deduced amino acid sequences of RDRPs within the genus Cypovirus showed 32% to 94% identities, while extent of homology between RDRPs in the genera Cypovirus and Oryzavirus, a genus most closely related, was approximately 26% identity. Both the genera Cypovirus and Oryzavirus might have originated from a common insect virus ancestor.