Tissue-specific alteration of gene expression and function by RU486 and the GeneSwitch system

The drug-inducible GeneSwitch (GS)-Gal4 transgene expression system is routinely used in Drosophila aging and behavioral studies to avoid the confounding effects related to genetic background mutations. Here, we report transcriptional and functional defects that are induced by RU486 in a stock- and tissue-dependent manner, such as defects in flight and mitochondrial gene expression. Our findings indicate that side effects induced by RU486 need to be considered when interpreting the observed phenotypes, and proper controls, consisting of ethanol-treated GS-Gal4 flies and RU486-induced expression of mock transgenes, should always be included Studies of the RU486 gene switch, 2 with a Gal4 transgene one w1118. 3 drug treated samples and 3 controls in each study.