Reproduction and preference to macronutrients have different relations to biological or chronological age in Drosophila

Abstract

Genetic manipulations, dietary composition and supplementations with varied drugs and natural compounds were shown to extend both the life- and health-span in different model organisms. An understanding of the mechanisms behind the beneficial properties of intervention includes the evaluation of physiological and molecular traits at certain time points that reflect the values at distinguished chronological age. Thus, if one cohort has a long-lived phenotype than measurements at certain time points represent the difference between organisms of different biological ages. We have compared reproduction and consumption of specific macronutrients for flies of the same cohort but related to different quartiles of chronological and biological age. We found that the decline in carbohydrate or protein consumption was stronger in the case of chronological rather than biological age. However, flies of biological or chronological quartile 4 consumed virtually the same amounts of macronutrients. The decline in reproduction was significantly reduced in relation to biological age. Thus, the decline was about 38-68% when within chronological quartiles 2 and 1 but only 4-31% for biological ones. The reproductive capacity was reduced by 86-93% in flies of chronological Q4 as compared to a 60-77% decrease for those of biological. Starting from quartile 2 biologically aged flies laid significantly higher number of eggs than flies of the same chronological quartile. Our results point out the significant difference in flies of the same biological and chronological quartile and raise the question about the suitability of comparison traits of organisms with different lifespans same chronological age.