Meeting Abstract
Drosophila melanogaster populations have undergone adaptive evolution along the latitudinal clines of North America and Australia. The genetic analyses of the clinal populations often reveal signatures of adaptive evolution on metabolism-related genes, yet the metabolic characteristics of clinal populations is poorly understood. Laboratory studies of metabolism in D. melanogaster inbred lines suggest that reduced sugar and fat levels are likely to correlate with decreased starvation resistance. To better understand metabolic traits and how they may influence survival in natural populations, we measured adult stored triglyceride and glucose levels, larval starvation response, and adult starvation response in 10 lines each from high and low latitude populations at 21 and 25C. We measured wing size in starved and well-fed rearing conditions, and found that while the high latitude populations were larger than the low latitude population when well-fed, there were no significant differences in wing size when starved, suggesting that both populations reached a similar threshold for starvation response. We measured whole body triglyceride and glucose levels using enzymatic assays on flies maintained at 25C and found overall higher levels of triglyceride and glucose in the high latitude populations, albeit non-significant. Further results and correlation between metabolic traits and starvation response at 21 and 25C will be presented.
