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

Transcriptional and functional defects induced by RU486 in skeletal muscle. a RNA-seq of thoracic skeletal muscle from Drosophila Act88F-GS flies treated with 100？μM RU486 for 10 days and untreated controls (–RU). RU486 represses the expression of nuclear-encoded mitochondrial genes, which is the first category of genes downregulated by RU486 (b). The transcriptome and the totality of mitochondrial genes are shown in gray and blue, respectively. The x axis reports the log ratio of gene expression changes of RU486-treated flies versus untreated controls, whereas the y axis reports the significance score, which is the –log10(P-value). Hence, values above the red line (P？<？0.05) correspond to significantly regulated genes. No GO categories are identified in genes with RU486-upregulated expression. c RU486 treatment decreases SDH activity in the muscle of Act88F-GS-Gal4 flies (n？=？4, SD, *P？<？0.05). d qRT-PCR analysis of skeletal muscle from Act88-GS-Gal4 flies treated with RU486. Consistent with RNA-seq data, qPCR analysis confirms that the expression of mitochondrial genes (CG10924, CG30493, CG41128, Hsp60, Las, and mRpS5) declines in response to RU486 treatment in a dose-dependent manner. Conversely, RU486 induces the expression of the cytoplasmic chaperones Hsp26 and Hsp83 (n？=？3, SD, *P？<？0.05). e In flies with muscle expression of GS-Gal4 (Mhc-GS-Gal4 and Act88F-Gs-Gal4), treatment for 1 week with 1, 10 or 100？μM RU486 leads to high percentages of flightless flies, compared with untreated controls. However, RU486 exerts minimal influence on the flight capacity of WT strains (w1118 and B3) and non-muscle GS-Gal4 strains with little or no GS-Gal4 expression in skeletal muscle (Act5c-GS-Gal4; FB-GS-Gal4, a combination of S32-GS-Gal4？+？S106-GS-Gal4). Supplementary Table 1 reports statistical analyse