Diet Restriction Modulates Heat Shock Gene Expression and Impairs Heat Shock Response in Drosophila melanogaster

Abstract

Diet restriction (DR) has been shown to extend life span in adult Drosophila melanogaster in a manner similar to that of calorie reduction in organisms from worms to primates. Long‐lived flies are smaller, have global down regulation of protein levels, and lower fecundity. We hypothesized that flies under diet restriction, although long‐lived under ideal conditions, would be more susceptible to environmental stresses. We fed adult flies control or diet restricted food for seven days and then performed qPCR on various transcripts known to be involved in stress response. We show here that various transcripts levels are modulated in response to diet restriction, particularly, HSP22, HSP70 and HSP83. We show also that diet restricted flies are limited in their ability to upregulate heat shock transcripts when exposed to heat stress and have an increased mortality rate under heat stress conditions.