Dietary Composition Regulates Drosophila Mobility and Cardiac Physiology. Sara Ginzberg, Brian Bazzell, Lindsey Healy, Robert Wessells. The University of Michigan, Ann Arbor, MI.

   The impact of dietary composition on exercise capacity is a subject of intense study in both humans and model organisms. Interactions between diet and genetics are a critical component in optimized dietary design. However, the genetic factors governing exercise response are still not well understood. The recent development of invertebrate models for endurance exercise is likely to facilitate study designs examining the conserved interactions between diet, exercise, and genetics. As a first step, we use the Drosophila model to describe here the effects of varying dietary composition on several physiological indices, including fatigue tolerance and climbing speed. We find that flies of two divergent genetic backgrounds optimize endurance and cardiac performance on relatively balanced low calorie diets. When flies are provided with unbalanced diets, diets higher in sugar than in yeast facilitate greater endurance at the expense of cardiac performance. Lastly, we use dissected cardiac muscle as a model muscle to analyze the effects of diet on intramuscular lipid storage, autophagy levels, and structural preservation of muscle fibers.