Epigenetic Effect of Modified Diet and Exercise on Drosophila Metabolic Phenotype and Cardiovascular Health

Abstract

Obesity is a growing world-wide epidemic. Overweight populations are prone to a variety of morbid conditions including diabetes type 2, cardiovascular diseases, and cancers. The catastrophic increase in obesity rates, which can later present as cardiovascular disease, is largely attributed to sedentary life style and a poor diet. Epigenetic studies show maternal obesity as a risk factor for metabolic syndromes in offspring. Furthermore, evidence suggests obese and diabetic fathers may also contribute to offspring metabolic phenotype. Experiments were designed to answer the question: does modified paternal diet and exercise produce transgenerational effects on offspring metabolic phenotype and cardiovascular health? Drosophila Melanogaster was used as a model because of its well-known genetics and short life cycle, making it ideal for transgenerational studies. Specifically, this research sought to look at the effects of high-fat and high sucrose diets and exercise on whole body composition, and particularly effects on cardiovascular health in Drosophila F0, and F1 generations. To test the effects of diet and exercise, male flies were exposed to either 14 days of high-fat, high-sucrose, exercise or control diet and then mated with control virgin females. Offspring were collected after hatching and subjected to a normal or modified diet for 14 days. After 14 days, animals were analyzed for triglyceride and trehalose/glucose levels in F0 and F1 generations. Fruit flies were also subjected to exercise for 14 days to measure the effects on phenotype. A vertical test was done before and after exercise to measure the effect of exercise on motor activity. Height climbed was measured in centimeters after vials were tapped down and flies were allowed to climb up for 5 seconds. Cardiovascular health was measured by beats per minute and was recorded at various time points throughout the 14 day diet. Results indicate a significant increase in amount of triglycerides and trehalose in exercise father offspring flies on a high-fat diet challenge than fat father offspring flies on a high-fat diet challenge. There was also a significantly increased heart rate for F0 flies on a high sucrose diet, and on an exercise regimen than flies on a high-fat diet. Fat father offspring on an exercise regimen had a significantly higher heart rate than control father offspring and exercise father offspring on an exercise regimen. Vertical test data showed a significantly higher level of motor activity from the exercise group than the control group through day 7, but then locomotor activity decreased post day 7 in the exercise group compared to the control. The combined data suggest paternal experience due to diet and exercise induces transgenerational effects in F1 male flies due to diet and exercise in the metabolic phenotype and cardiovascular health.