Sex-specific effects of protein and carbohydrate intake on reproduction but not lifespan in Drosophila melanogaster.

Modest dietary restriction extends lifespan (LS) in a diverse range of taxa and typically has a larger effect in females than males. Traditionally, this has been attributed to a stronger trade-off between LS and reproduction in females than in males that is mediated by the intake of calories. Recent studies, however, suggest that it is the intake of specific nutrients that extends LS and mediates this trade-off. Here, we used the geometric framework (GF) to examine the sex-specific effects of protein (P) and carbohydrate (C) intake on LS and reproduction in Drosophila melanogaster. We found that LS was maximized at a high intake of C and a low intake of P in both sexes, whereas nutrient intake had divergent effects on reproduction. Male offspring production rate and LS were maximized at the same intake of nutrients, whereas female egg production rate was maximized at a high intake of diets with a P:C ratio of 1:2. This resulted in larger differences in nutrient-dependent optima for LS and reproduction in females than in males, as well as an optimal intake of nutrients for lifetime reproduction that differed between the sexes. Under dietary choice, the sexes followed similar feeding trajectories regulated around a P:C ratio of 1:4. Consequently, neither sex reached their nutritional optimum for lifetime reproduction, suggesting intralocus sexual conflict over nutrient optimization. Our study shows clear sex differences in the nutritional requirements of reproduction in D. melanogaster and joins the growing list of studies challenging the role of caloric restriction in extending LS.

Jensen K ，McClure C ，Priest NK ，Hunt J ... -  《-》

Sex-specific fitness effects of nutrient intake on reproduction and lifespan.

Maklakov AA ，Simpson SJ ，Zajitschek F ，Hall MD ，Dessmann J ，Clissold F ，Raubenheimer D ，Bonduriansky R ，Brooks RC ... -  《CURRENT BIOLOGY》

Nutrients, not caloric restriction, extend lifespan in Queensland fruit flies (Bactrocera tryoni).

Fanson BG ，Weldon CW ，Pérez-Staples D ，Simpson SJ ，Taylor PW ... -  《-》

Little evidence for intralocus sexual conflict over the optimal intake of nutrients for life span and reproduction in the black field cricket Teleogryllus commodus.

There is often large divergence in the effects of key nutrients on life span (LS) and reproduction in the sexes, yet nutrient intake is regulated in the same way in males and females given dietary choice. This suggests that the sexes are constrained from feeding to their sex-specific nutritional optima for these traits. Here, we examine the potential for intralocus sexual conflict (IASC) over optimal protein and carbohydrate intake for LS and reproduction to constrain the evolution of sex-specific nutrient regulation in the field cricket, Teleogryllus commodus. We show clear sex differences in the effects of protein and carbohydrate intake on LS and reproduction and strong positive genetic correlations between the sexes for the regulated intake of these nutrients. However, the between-sex additive genetic covariance matrix had very little effect on the predicted evolutionary response of nutrient regulation in the sexes. Thus, IASC appears unlikely to act as an evolutionary constraint on sex-specific nutrient regulation in T. commodus. This finding is supported by clear sexual dimorphism in the regulated intake of these nutrients under dietary choice. However, nutrient regulation did not coincide with the nutritional optima for LS or reproduction in either sex, suggesting that IASC is not completely resolved in T. commodus.

Rapkin J ，Archer CR ，Grant CE ，Jensen K ，House CM ，Wilson AJ ，Hunt J ... -  《-》

Lifespan and reproduction in Drosophila: New insights from nutritional geometry.

Lee KP ，Simpson SJ ，Clissold FJ ，Brooks R ，Ballard JW ，Taylor PW ，Soran N ，Raubenheimer D ... -  《-》