JNK-dependent elevated levels of FAO upregulate upd3 expression. (A–D′) Increase in the reporter TRE-DsRed expression (red) in the PCs of HSD-fed flies (B and B′) as compared to that observed in flies reared on ND (A and A′) remains unaltered even after attenuating Whd function in the PCs (C–D′). Phalloidin (green) marks the cardiac tube and the alary muscles. A, B, C, and D show TRE-dsRed expression in grayscale; A′, B′, C′, and D′ represent the merged images of the two colors. (E) Quantification of the mean fluorescence intensity for TRE-DsRed expression in the PCs of HSD-fed flies upon attenuating Whd function in the PCs. The dots represent the number of PCs analyzed for each genotype. (F) Changes in the level of whd transcripts in the RNA isolated from PCs and cardiac tube of ND- and HSD-fed flies upon attenuating JNK pathway in the PCs. The transcript levels are normalized to that of the constitutive ribosomal gene rp49. (G) Overexpression of whd remarkably recues the drop in pericardial upd3 expression of HSD-fed flies as observed upon attenuating JNK signaling in the PCs. The transcript levels are normalized to that of the constitutive ribosomal gene rp49. (H) Signaling cascade triggered by JNK in regulating upd3 expression in the PCs of HSD-fed flies. Genotypes are as mentioned. Data are represented as mean ± SD. P values (ns ≥ 0.05, ***P < 1 × 10−3) were obtained by two-way ANOVA with correct with Tukey’s multiple-comparison test (E, F, and G). Scale bars, 50 μm.
