Fig. 4.

Levels of energy storage metabolites in dSirt4 knockout (KO) flies during fasting. (A) TAG levels in control (black) and dSirt4 KO (red) male flies, assayed every 8 h over a 24-h fasting period. Corresponding measurements for glycogen (B), trehalose (C), and glucose (D) under the same conditions are shown. Data represent the mean of five biological replicates, with five flies per replicate. All metabolite measurements were normalized against total protein in each sample and reported in units of milligrams per milliliter. Error bars represent SEM. * = 0.01 < P < 0.05; ** = 0.001 < P < 0.01; *** = P < 0.001 (unpaired two-tailed t test). n.s., not significant.