The analysis of differentially expressed genes (RNA-Seq) in the fat bodies of the researched groups of D. melanogaster females with the use of RNA-Seq profiling revealed changes in the signal pathways related to proteolysis/digestion, heat shock protein 23, and in the tightly linked stress-inducible humoral factor Turandot gene network

Understanding how repeated stress affects metabolic and physiological functions in the long run is of crucial importance for evaluating anthropogenic pressure on the environment. Here, we investigated fecundity, longevity and metabolism in D. melanogaster females exposed to short-term heat stress episodes (38°C, 1 h) repeated daily or weekly. Daily stress was shown to cause a significant decrease in both fecundity and longevity, as well as in body mass and fat content, but a significant increase in carbohydrates (trehalose and glucose) content. Weekly stress in the first two weeks after eclosion did not affect the longevity, body mass and carbohydrate metabolism, but resulted in a significant decrease in fat content and a significant increase in the total level of fecundity, despite sharp fecundity drops on the exact days of stressing. Then, we used these two stress modes to research the long-term effect of mild heat stress on transcriptional profiles of the D. melanogaster fat bodies (the vital organ accumulating and releasing the energy reserves of the insect organism when necessary). The analysis of differentially expressed genes in the fat bodies of the researched groups of D. melanogaster females with the use of RNA-Seq profiling revealed changes in the signal pathways related to proteolysis/digestion, heat shock protein 23, and in the tightly linked stress-inducible humoral factor Turandot gene network. There is also evidence of the transcriptome undergoing coordinated extensive splicing landscape alteration in DEGs set.