Fig. 4: Gene expression and functional validation of Dgat2 in skeletal muscle in WT and obesity models.

a Schematic representation of de novo triacylglycerol synthesis with metabolite intermediates and important genes (italic bold) encoding enzymes. Color indicates condition (gray WT, orange HFD, purple Sk2). Down arrows indicate downregulation of gene expression (fold change ≥1.25). Asterisks indicate p-value ≤ 0.05. b Expression level of gene Dgat2 under ALF and TRF in WT and obese models. N = 5 time points in WT and Sk2. N = 6 time points in HFD. c Flight performance of female flies with Act88F-Gal4-driven Dgat2 KD at 1, 3, 5, and 7 weeks of age. One RNAi line was tested. Flight indices were plotted as cohorts of 10–20 flies. # of cohorts per RNAi line per age group = 5–6; # of flies per genotype per age = 65–102. Details of precise N are in Source Data. Mean ± SEM. Two-sided unpaired t-tests. d Fluorescence images of the IFMs from 3-week-old female flies with Act88F-Gal4-driven KD of Dgat2 upon staining with phalloidin (green) and Nile Red (red puncta). Smaller sizes of lipids (arrows) were detected in IFMs of flies with Dgat2 KD, compared with age-matched control. The scale bar is 20 µm. e, f Intramuscular lipid quantification of 3-week-old females (lipid droplet size (e) and density (f)). N = 9 from three flies’ IFM per genotype. Mean ± SEM. Two-sided unpaired t-tests. g Flight performance of female flies with DJ694-Gal4-driven Dgat2 KD at 1, 3, 5, and 7 weeks of age. Two independent fly lines were tested. Flight indices were plotted as cohorts of 10–20 flies. Results from independent RNAi lines were indicated with symbol circle or triangle. # of cohorts per RNAi line per condition = 3–4; # of flies per genotype per age group = 95–137. Details of precise N are in Source Data. Mean ± SEM. Two-sided unpaired t-tests. h Fluorescence images of the IFMs from 3-week-old female flies with DJ694-Gal4-driven Dgat2 KD upon staining with phalloidin (green) and Nile Red (red puncta). The scale bar is 20 µm. i, j Intramuscular lipid quantification of 3-week-old females (lipid droplet size (i) and density (j)). N = 9 from three flies’ IFM per genotype. Mean ± SEM. Two-sided unpaired t-tests. Source data are provided as a Source Data file.