Ruchitha, B. G. | bioRxiv Science

bioRxiv2024

Effect of developmental and adult diet composition on reproductive aging in Drosophila melanogaster

Diet significantly affects reproductive outcomes across species, yet the precise effects of macronutrient compositions beyond caloric intake on reproductive aging are understudied. Existing literature presents conflicting views on the fertility impacts of nutrient-rich versus nutrient-poor developmental diets, underscoring a notable research gap. This study addresses these gaps by examining effects of isocaloric diets with varied protein-to-carbohydrate ratios during both developmental and adult stages on reproductive aging of a large, outbred Drosophila melanogaster population (n = [~]2100). Our results clearly demonstrate an age-dependent dietary impact on reproductive output, initially dominated by the developmental diet, then by a combination of developmental and adult diets in early to mid-life, and ultimately by the adult diet in later life. Importantly, we found that the effects of developmental and adult diets on reproductive output are independent, with no significant interaction. Further investigations into the mechanisms revealed that the effect of developmental diet on fecundity is regulated via ovarioles formation and vitellogenesis; while, the effect of adult diet on fecundity is mostly regulated only via vitellogenesis. These insights resolve disputes in the literature about dietary impacts on fertility and offer valuable perspectives for optimizing fertility strategies in improving public health and conservation efforts in this changing world. HighlightsO_LIEffect of developmental and adult diet composition on reproduction is age-dependent C_LIO_LIDevelopmental diet affects early-life; adult diet late-life; and both affect mid-life C_LIO_LIBut the effect of developmental and adult diets do not interact with each other C_LIO_LIDevelopmental diet regulates reproduction via ovarioles formation and vitellogenesis C_LIO_LIWhereas, adult diet regulates reproduction via differential vitellogenesis across age C_LI

ecology↗

bioRxiv2022

Selection for greater dispersal in early life leads to increased rate of age-dependent decline in locomotor activity and shorter lifespan

Locomotor activity is one of the major traits that is affected by age. Greater locomotor activity is also known to evolve in the course of dispersal evolution. However, the impact of dispersal evolution on the functional senescence of locomotor activity is largely unknown. We addressed this knowledge gap using large outbred populations of Drosophila melanogaster selected for increased dispersal. We tracked locomotor activity of these flies at regular intervals until a late age. Longevity of these flies was also recorded. We found that locomotor activity declines with age in general. However interestingly, activity level of dispersal selected populations never drops below the ancestry-matched-controls, despite the rate of age-dependent decline in activity of the dispersal selected populations being greater than their respective controls. Dispersal selected population was also found to have shorter lifespan as compared to its control, a potential cost of elevated level of activity throughout their life. These results are crucial in the context of invasion biology as contemporary climate change, habitat degradation, and destruction provide congenial conditions for dispersal evolution. Such controlled and tractable studies investigating the ageing pattern of important functional traits are important in the field of biogerontology as well.

evolutionary biology↗