Splice‐activated <i>UAS</i> hairpin vector gives complete RNAi knockout of single or double target transcripts in <i>drosophila melanogaster</i>

Abstract

A DNA vector giving complete RNAi knockout of nec is described. A stable hairpin-loop is inactive, but introduction of an intronic spacer activates the RNAi response. Similar constructs for the forked, Drs, and BG4 transcripts also give targeted suppression. Furthermore, "splice activation" can affect two trigger sequences, in a double knockout vector. We suggest that the splicing mechanism might cause localized "melting" of RNA followed by reannealing. This process would eliminate mismatched regions expected from hybridization of complementary RNA strands under physiological conditions. Unlike in plants, we show that the RNAi response in Drosophila is cell autonomous and our UAS-f::nec-dsRNA strain forms a useful tool to visualize the domain of expression of Gal4 drivers.