Biology subjects

Chandrakanth, M.

Publications and source records attributed to Chandrakanth, M..

4 recordsLinked to original sources

bioRxiv2026

Nutritional history affects stress-resistance architecture across ageing and sex

Diet can influence lifespan and age-dependent physiological function, but how nutrition during development and adulthood affects relationships among stress resistance traits across age remains unclear. Using an isocaloric full-factorial larval x adult diet design in outbred Drosophila melanogaster, we tested how protein- and carbohydrate-biased diets affected starvation, desiccation, cold, osmotic, and heat resistance across the adult life course and sex. We also measured whole-body triacylglyceride, protein, body weight, and water content, and compared responses with matched lifespan and reproductive-output data. Resistance declined across the adult life course, but the traits did not vary as a single phenotype: among the traits included in the covariance analysis, desiccation, osmotic, and heat resistance formed a tightly correlated core, whereas starvation resistance remained comparatively peripheral in both sexes. Developmental diet produced trait-specific effects, whereas protein-biased adult diet favoured heat and osmotic resistance, paralleling effects on lifespan and reproductive output, but had opposite effects on starvation and cold resistance in specific contexts. Thus, nutrition alters rather than uniformly improves stress resistance, and covariance among resistance traits does not necessarily predict how those traits respond to nutritional perturbation.

ecology↗

bioRxiv2024

Additive and context-dependent effects of developmental and adult diet on life-history traits and their associations in outbred Drosophila melanogaster population

Life-history traits such as body size, reproduction, survival, and stress resistance are fundamental to an organisms fitness and are highly influenced by nutritional environments across life stages. In this study, we employed a full factorial experimental design to investigate the effects of isocaloric diets (diets with equal caloric content but differing macronutrient composition) on key life-history traits in an outbred Drosophila melanogaster population. Our results demonstrated significant diet-induced plasticity, with male wing length (a proxy for body size) being influenced by the developmental diet; males reared on carbohydrate-rich developmental diets had larger wings as adults. Fertility increased with protein-rich diets at both developmental and adult stages, reaffirming the critical role of dietary protein in enhancing reproductive success. Lifespan exhibited sexually dimorphic responses to diet: carbohydrate-rich developmental diets extended male lifespan, while carbohydrate-rich adult diets reduced lifespan in both sexes. Stress resistance traits, including starvation and desiccation resistance, were unaffected by developmental diets but were influenced by adult diets, with carbohydrate-rich adult diets enhancing survival under both stress conditions in males and females. Importantly, while most traits exhibited additive effects of nutrition across life stages, a marginal interaction for male starvation resistance suggests that developmental and adult diets can interact in a trait- and sex-specific manner. Moreover, associations between dietary effects on life-history traits were context-dependent, driven primarily by adult diets and varying by sex. These findings emphasize the profound role of stage-specific nutritional environments in modulating life-history traits and their correlations, offering valuable insights into how organisms may adapt to changing ecological conditions and highlighting the importance of considering both developmental and adult dietary contexts in evolutionary studies.

evolutionary biology↗

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↗

bioRxiv2023

Diet-induced plasticity of life-history traits and gene expression in outbred Drosophila melanogaster population

Food is fundamental for the survival of organisms, governing growth, maintenance, and reproduction through the provision of essential macronutrients. However, access to food with optimum macronutrient composition, which will maximize the evolutionary fitness of an organism, is not always guaranteed. This leads to dietary mismatches with potential impacts on organismal performance. To understand the consequences of such dietary mismatches, we examined the effects of isocaloric diets varying in macronutrient composition on eight key organismal traits spanning across the lifespan of a large outbred Drosophila melanogaster population (n [~] 2500). Our findings reveal that carbohydrate-reduced isocaloric diets correlates to accelerated pre-adult development and boosts reproductive output without impacting pre-adult viability and body size. Conversely, an elevated dietary carbohydrate content correlated to reduced lifespan in flies, evidenced by accelerated functional senescence including compromised locomotor activity and deteriorating gut integrity. Furthermore, transcriptomic analysis indicated a substantial difference in gene regulatory landscapes between flies subject to high carbohydrate vs high protein diet, with elevated protein levels indicating transcriptomes primed for reduced synthesis of fatty acids. Taken together, our study helps advance our understanding of the effect of macronutrient composition on life history traits and their interrelations, offering critical insights into potential adaptive strategies that organisms might adopt against the continual dietary imbalances prevalent in the rapidly evolving environment.

evolutionary biology↗