UASt sequences drive expression of an inverted repeat, in a head-to-head orientation, corresponding to the first 500bp of the Diap2 coding sequence. A 282bp-long genome fragment of the Ret gene, which contains introns 5 and 6 of this gene, lies between the two Diap2 fragments to enhance the RNAi effect.
Flies that express Iap2dsRNA.Scer\UAS in the fat body, under the control of Scer\GAL4c564, show no detectable defects. However, the immune response to infection with the Gram-negative bacteria P.carotovorum, as determined by induction of Dpt, is strongly reduced.
Transcription from the P{UAS-Iap2.dsRNA} transgenic construct produces Iap2 dsRNA, resulting in dsRNA interference (RNAi) of the Iap2 gene.