Double stranded (ds)RNA molecules produced during viral replication are recognized by the
innate immune system and induce an RNA interference (RNAi) response, resulting in sequencespecific gene silencing at the post-transcriptional level. Because of its specificity, RNAi has become a widely used reverse genetics tool. In addition, several recent studies have shown that RNAi may also contribute to novel, promising strategies for selectively controlling agricultural pests or for curing viral infections in beneficial insects. However, it is well known that many economically important insect species are refractory for an effective RNAi response. Therefore, an improved understanding of processes affecting RNAi efficiency is of high importance from the viewpoint of both basic and applied research.
This FWO proposal is based on an original hypothesis that persistent viral infections may interfere with RNAi efficiency in insects. At present, the causes for variability of the RNAi response are not known and the impact of chronic viral infections on RNAi in insects has not been investigated.
Newly identified viruses in populations of three important insects, bumblebees (Bombus
terrestris), locusts (Schistocerca gregaria) and caterpillars (Spodoptera littoralis), as well as viruses already available to the consortium, will be tested for their effects on the RNAi efficiency by both in vitro and in vivo approaches, followed by investigating the molecular mechanism(s) of RNAi inhibition.