Dietary protein defines stress resistance, oxidative damages and antioxidant defense system in Drosophila melanogaster

Dietary interventions have been previously shown to influence lifespan in diverse model organisms. Manipulations with macronutrients content including protein and amino acids have a significant impact on various fitness and behavioral traits in the fruit fly Drosophila melanogaster. Therefore, we asked if yeast amount of the diet could influence stress resistance and antioxidant defense system in Drosophila. We examined the effects of four diets differing in the relative level of yeast, as a source of protein, on resistance to cold, heat, starvation and oxidative stress induced by menadione as well as activities of antioxidant enzymes and levels of oxidative stress markers. Protein restriction as well protein-enriched diet led to a reduction of survival under starvation and oxidative stress conditions. However, enhanced resistance to heat shock was affected by high yeast concentration in the diet. Also, protein-rich diets resulted in higher activity of antioxidant enzymes. Increased levels of protein thiols, low-molecule mass thiols, lipid peroxides in response to high yeast concentration in the diet were detected in females only. Thus, we can assume that consumption of a high protein diet could induce oxidative stress in fruit fly

Protein content in the parental diet affects cold tolerance and antioxidant system state in the offspring Drosophila

Dietary nutrients are the key determinants of the lifespan and metabolic health. The content of specific dietary compounds in the parental diet can epigenetically affect the physiological state of the offspring. Here, we studied how variable dietary protein content in the diet of parental generation affects antioxidant capacity of Drosophila melanogaster adult offspring. The dry yeast concentration ranging from 0.25% to 15% in the parental diet was the only variable in the experiments, whereas subsequent generation was kept on a diet of the same composition. We found, that flies fed with yeast-restricted (0.25%) diet produced F1 male flies with a higher cold tolerance and higher activity of the second-line antioxidant enzymes whereas in F1 females no effect of parental diet composition on the cold tolerance, catalase, GST, G6PDH, IDH activity and low thiols content was detected. The results suggest that nutrient-dependent changes of genes expression in the flies of paternal generation differently affect the stress response of males and females of the first-generation offspring

Developmental diet defines metabolic traits in larvae and adult Drosophila

The influence of the developmental nutrition on adult metabolism and overall performance becomes a hot topic of modern evolutionary biology. We used fruit fly Drosophila melanogaster as a model and experimental nutrition media composed of different sucrose content (S) and dry yeast content (Y): 0S:2Y, 20S:2Y or 0S:5Y, 20S:5Y to show that the developmental nutrition conditions define metabolism in larvae and adults. The level of glucose, glycogen, triglycerids and total lipids in the larvae and flies body were measured with the diagnostic assay kits. We found that individuals developed on either low-yeast or high-sugar diet showed delayed developmental rate. When kept on the diets with high sucrose content the larvae and adult flies had lower weight and higher amount of lipids as energy reserves. Restriction of dry yeast content in the diet of larvae led to a decrease in glycogen storage and protein levels in larvae and adult flies. The results obtained indicate that the metabolic traits revealed in adult flies are the result of nutrition during development and may be associated with mechanisms of organisms adaptation to the developmental nutritional conditions

Within-diet variation in rates of macronutrient consumption and reproduction does not accompany changes in lifespan in Drosophila melanogaster

Interventions such as caloric or dietary restriction extend lifespan in organisms spanning from yeast to primates. Despite its positive influence on longevity, dietary restriction has been found to negatively affect reproduction. Many studies have reported negative correlations between lifespan and reproductive characteristics (such as mating rate, fecundity, reproductive period, and others). Such correlation gives the appearance of a resource-based trade-off between these two life-history traits. Here, we have used nutritional geometry to confirm previous findings in flies that dietary macronutrient balance (protein-to-carbohydrate ratio, P:C) impacts both lifespan and reproduction, such that across a series of diets differing in P:C, maximum lifespan was observed at a lower P:C (1:8) than that which supported highest fecundity (1:1.5). We have then addressed the question whether variation among Drosophila melanogasterMeigen (Diptera: Drosophilidae) fruit flies in food intake and egg production within a single dietary treatment is negatively associated with within-diet variation in lifespan, as might be expected under a resource-based trade-off. There was no such associat