Interaction between non-structural protein Pns10 of rice dwarf virus and cytoplasmic actin of leafhoppers is correlated with insect vector specificity.

Many insect-transmissible pathogens are transmitted by specific insect species and not by others, even if the insect species are closely related. The molecular mechanisms underlying such strict pathogen-insect specificity are poorly understood. Rice dwarf virus (RDV), a plant reovirus, is transmitted mainly by the leafhopper species Nephotettix cincticeps but is transmitted ineffectively by the leafhopper Recilia dorsalis. Here, we demonstrated that virus-containing tubules composed of viral non-structural protein Pns10 of RDV associated with the intestinal microvilli of N. cincticeps but not with those of R. dorsalis. Furthermore, Pns10 of RDV specifically interacted with cytoplasmic actin, the main component of microvilli of N. cincticeps, but not with that of R. dorsalis, suggesting that the interaction of Pns10 with insect cytoplasmic actin is consistent with the transmissibility of RDV by leafhoppers. All these results suggested that the interaction of Pns10 of RDV with insect cytoplasmic actin may determine pathogen-vector specificity.