Antioxidant Protection Against Ethanol-induced Phenotypes in Drosophila melanogaster

We are investigating the cellular mechanisms by which oxidative damage leads to developmental alterations, as well as whether ethanol’s developmental effects are through an increase in oxidative stress.  Our previously published results show that developmental exposure to ethanol in Drosophila melanogaster leads to reduced viability and a significant developmental delay, and that these phenotypes can be ameliorated with transgenic expression of Drosophila insulin-like proteins (Dilps) (French, McClure, and Heberlein, 2011). Previous research in our lab indicates that mutation of the fly homolog of PDK in the PI3K insulin-signaling pathway suppresses ethanol-induced developmental lethality.  This mutation has previously been shown to lead to resistance to oxidative stress. This fact, combined with the fact that ethanol is known to cause oxidative stress, led us to hypothesize that oxidative stress might be at least partially responsible for the ethanol-induced phenotypes.  To test this hypothesis, we are testing whether experimental reduction in oxidative stress can rescue ethanol-induced phenotypes.  We have carried out trials with the anti-oxidant vitamins thiamine, vitamin C, and vitamin E in flies raised with and without ethanol to determine the rates of delay and survival.  We found that Thiamine, when added to fly food, was able to ameliorate the ethanol-induced developmental phenotypes.  Future work will include testing additional antioxidant vitamins, as well as biochemical evaluation of the expression of cellular antioxidant enzymes in ethanol-exposed larvae. Finally, we will attempt to prevent ethanol-induced lethality and developmental delay through overexpression of anti-oxidant enzymes using the UAS-GAL4 system.