Effect of metabolites on stress, adaptation and longevity in laboratory populations of Drosophila flies

Metabolites like lipid and carbohydrate have significant roles on starvation, desiccation and longevity and differ in natural and laboratory populations of Drosophila. Five laboratory populations of Drosophila ananassae have been subjected to paraquat-induced mortality and longevity, desiccation resistance, body size and ovariole number and tested for different metabolites (lipid, carbohydrate and water), fecundity and polymorphic chromosome inversions in each sex. Paraquat dose-response has clinal variation and means that paraquat mortality at different concentrations is significantly altered among males only. The overall mean ovariole number varies significantly (P<<0.001) among different populations and one-way ANOVA suggests significant variations (P<<0.001) with mean fecundity and latitude. Only female longevity varies significantly among five different populations (P<<0.001). Fecundity shows positive correlations with the longevity and suggests a possible role of different metabolites in keeping the cost effect. Two-way ANOVA among mean water, lipid and carbohydrate contents in both sexes of different populations suggest significant differences among metabolites (P<<0.001), between males and females (P<<0.001, d.f.=1) and for their interactions with each other (P<<0.001) also. Significant differences are found for mean longevity, lipid and carbohydrate contents in both sexes of different populations in a two-way ANOVA analysis (P<<0.001), which suggests possible roles in their utilization at different levels during adaptation and stress. Longevity is affected significantly (P<<0.001) by desiccation resistance also. Different chromosome inversions and their combinations show significant variations and sexual dimorphism with latitude and thorax length (P<<0.001) and their roles are discussed in achieving adaptation, stress resistance and longevity.