TospovirusReplication in Insect Vector Cells: Immunocytochemical Evidence that the Nonstructural Protein Encoded by the S RNA of Tomato Spotted Wilt Tospovirus Is Present in Thrips Vector Cells

Tomato spotted wilt tospovirus (TSWV) is an insect-transmitted virus that is the type member of the Tospovirus genus, which is the only genus in the family Bunyaviridae containing viruses that infect plants. Direct evidence that Tospoviruses replicate in their thrips vectors has been difficult to obtain because of limitations to definitively detect replicative intermediates of TSWV or to immunolabel vector tissues. A nonstructural protein is encoded by the small RNA of TSWV, and translation of the NSs protein occurs from a subgenomic RNA formed after transcription of viral sense RNA. This protein is designated as nonstructural because it is found only in TSWV-infected cells and has not been found in assembled virions