Sex-biased metabolic programming in Drosophila via paternal white rice exposure

High-glycemic foods such as white rice (WR) are major dietary contributors to metabolic disorders, yet paternal transmission of their metabolic effects remains unknown. This study investigated whether paternal WR feeding influences metabolic phenotypes in Drosophila (fruit fly) offspring. Fly eggs were reared on either a control, 50% WR, or 50% brown rice (BR) during development, and adult males were subsequently maintained on respective diets prior to mating with virgin females maintained on a normal diet. The resulting F1 and F2 offspring were maintained on either a normal diet or a high-sugar diet (HSD) to assess baseline metabolic effects and susceptibility to dietary stress. Metabolic parameters including body weight, locomotor activity, glucose, glycogen, triglycerides, trehalose, and expression of insulin-like peptide 2 (dILP2) and acetyl-CoA carboxylase (ACC) were evaluated. The female F1 and F2 offspring of WR-fed flies raised on a normal diet exhibited elevated levels of haemolymph glucose, trehalose, and triglyceride but without significant change in locomotor activity. The male offspring showed increased triglyceride levels and altered locomotor performance. The expression of ILP2 and ACC in the offspring was sex-dependent. The HSD-fed offspring of the paternal WR group showed a worsened metabolic state. The metabolic indices in the offspring born to the BR group were similar to the control. The findings suggest that the paternal consumption of white rice induced sex-specific metabolic changes in their offspring, and the female offspring were at higher risk for glucose and lipid homeostasis disorders.