Nutritional history affects stress-resistance architecture across ageing and sex

The nutritional history of an organism can have a significant impact on its stress-resistance architecture, particularly as it ages and varies by sex, according to a new study. Researchers used an isocaloric full-factorial larval x adult diet design in outbred Drosophila melanogaster to investigate how protein- and carbohydrate-biased diets during different life stages affect various stress resistance traits.

They evaluated the effects on starvation, desiccation, cold, osmotic, and heat resistance throughout the adult life course and both sexes, as well as measured whole-body triacylglyceride, protein, body weight, and water content.

The study found that stress resistance declined across the adult life course, but the traits did not behave as a single unified phenotype. Instead, desiccation, osmotic, and heat resistance formed a tightly correlated core, while starvation resistance remained comparatively peripheral in both sexes. The researchers discovered that the developmental diet produced trait-specific effects, whereas a protein-biased adult diet favored heat and osmotic resistance, which aligned with its effects on lifespan and reproductive output. However, it had opposite effects on starvation and cold resistance in certain contexts.

These findings suggest that nutrition can alter rather than uniformly improve stress resistance, and covariance among resistance traits does not necessarily predict how those traits will respond to nutritional perturbation. The results highlight the importance of considering the timing and type of nutrition when evaluating stress resistance and the potential implications for the overall health and longevity of organisms.