Purine and folate metabolism as a potential target of sex-specific nutrient allocation in Drosophila and its implication for lifespan-reproduction tradeoff.

The reallocation of metabolic resources is important for survival during periods of limited nutrient intake. This has an influence on diverse physiological processes, including reproduction, repair, and aging. One important aspect of resource allocation is the difference between males and females in response to nutrient stress. We identified several groups of genes that are regulated in a sex-biased manner under complete or protein starvation. These range from expected differences in genes involved in reproductive physiology to those involved in amino acid utilization, sensory perception, immune response, and growth control. A striking difference was observed in purine and the tightly interconnected folate metabolism upon protein starvation. From these results, we conclude that the purine and folate metabolic pathway is a major point of transcriptional regulation during resource allocation and may have relevance for understanding the physiological basis for the observed tradeoff between reproduction and longevity.