Effect of diet quality and associated metabolic changes in adult stress response and life-history traits in Drosophila ananassae

While investigating the role of larval nutrition in adult stress tolerance in Drosophila ananassae during the course of the previous study, we have assumed certain hypothesis behind the mechanisms underlying ecological adaptation of this species. Keeping this in view, the aim of the present study was to evaluate the mechanistic role of diets during stress response at cellular and metabolic level in D. ananassae. To gain insight into the molecular and physiological basis of variation in stress tolerance in flies developed on different nutritional regimes, we identified a novel factor that depositions of uric acid crystals in Malpighian tubules of flies has a regulatory role in tolerance to desiccation. To assess the role of diet in variation in the physiological process by immunostaining method, we checked (Na+/K+) ion-pump in Malpighian tubules. Results suggest that physiological activities of flies fed on carbohydrate food are higher as indicated by the elevated level of (Na+/K+)-ATPase ion transport. We also found significant dietary effects on egg production and egg-to-adult viability, suggesting a possible trade-off between the traits investigated. Expression of Hsp60 was also modulated by diet. Hsp60 was highly expressed in carbohydrate and protein-enriched medium compared to normal food.