Abstract

Overnutrition due to chronic high-sugar (HS) feeding has been shown to reduce lifespan and elicit type II diabetes-like pathophysiology phenotypes in Drosophila melanogaster. We are using an experimental evolution approach in large, outbred Drosophila populations using a HS diet as the selective pressure. This has produced rapid phenotypic adaptation including a significant increase in survival for selected flies on the HS diet. One mechanism by which flies might reduce the effects of a HS diet would be to reduce consumption. Thus, we hypothesized that there would be differences in feeding behavior between control and adapted populations. Four control and four HS-selected populations were separated by sex and fed either control (5% w/v sucrose) or HS (34% w/v) medium supplemented with 2% FD&C Blue #1 for two hours and spectrometry was used to quantify the amount consumed. Consistent with previous findings, females ate more than males. Some HS-adapted fly populations exhibited an overall reduction in feeding, whereas others showed a greater sensitivity to calorie content, compared with controls. In the selected population with the longest lifespan and healthspan, there was no difference in females’ feeding on control food, but a significant reduction was observed when eating HS food. This is consistent with the greater triacylglycerol (TAG) content in HS-fed control flies, compared with selected flies. Moving forward, we hope to probe the role of acetylcholine signaling in producing the feeding differences between the control and adapted populations.