Oxidative stress resistance in insulin-signaling impaired male and female Drosophila melanogaster
Authors: Jessica Alvarez; Juan Rafael Riesgo-Escovar
Affiliation: UNAM, Queretaro, Mx
Keywords: g. oxidative damage; n. diabetes
Diabetes encompasses a group of metabolic disorders characterized by disglycemia, caused by insufficient insulin production or its inefficient signaling, and entails detrimental consequences for the patient's quality of life. Drosophila melanogaster has an evolutionarily conserved insulin signaling pathway. We set to understand how an organismal deficiency in insulin signaling in adult male and female flies affects different aspects of the fly's life, particularly the response to oxidative stress.
We exposed InR (the insulin receptor fly homolog) and dS6K (the ribosomal protein S6 kinase beta-1 fly homolog, under the control of TORC1, also regulated by insulin signaling) heteroallelic mutants, as well as wildtype controls with the same genetic background, to different prooxidant compounds. We found that females have higher lipid and carbohydrate accumulation and show better resistance to oxidative stress (H2O2) than males. A heterozygous mutation in Keap1 (a negative regulator of CncC, a master regulator of the antioxidant response) only rescued the phenotype of mutant InR males. We conclude that the type of oxidant fed to the fly and the genetic manipulation of the antioxidant response affected differentially the survival of males and females.