Data from: Adult dietary protein has age- and context-dependent effects on male post-copulatory performance

The highly-conserved effect of dietary protein restriction on life-span and ageing is observed in both sexes and across a vast range of taxa. This extension of life-span is frequently accompanied by a reduction in female fecundity and it has been hypothesised that individuals may reallocate resources away from reproduction and into somatic maintenance. However, effects of dietary protein restriction on male reproduction are less consistent, suggesting that these effects may depend on other environmental parameters. Using the neriid fly, Telostylinus angusticollis, we examined age-specific effects of adult dietary protein restriction on male post-copulatory reproductive performance (fecundity and offspring viability). To explore the context-dependence of these effects, we simultaneously manipulated male larval diet and adult mating history. We found that protein-restricted males sired less viable offspring at young ages, but offspring viability increased with paternal age and eventually exceeded that of fully-fed males. The number of eggs laid by females was not affected by male dietary protein, whereas egg hatching success was subject to a complex interaction of male adult diet, age, larval diet, and mating history. These findings suggest that effects of protein restriction on male reproduction are highly context-dependent, and cannot be explained by a simple reallocation of resources from reproduction to somatic maintenance. Rather, these effects appear to involve changes in the scheduling of male reproductive investment with age.膳食蛋白质限制（dietary protein restriction）对寿命与衰老的高度保守效应在两性中均存在，且广泛分布于各类生物类群中。该寿命延长现象常伴随雌性繁殖力（fecundity）下降，因此有假说提出，个体可能将资源从繁殖活动重新分配至体细胞维持（somatic maintenance）过程。然而，膳食蛋白质限制对雄性繁殖的效应并不一致，提示这类效应可能依赖于其他环境参数。本研究以斑眼蝇科（neriid fly）的窄茎眼蝇（Telostylinus angusticollis）为实验对象，探究了成年期膳食蛋白质限制对雄性交配后繁殖性能（post-copulatory reproductive performance，包括繁殖力与后代存活力（offspring viability））的年龄特异性效应；为探明这些效应的背景依赖性，我们同时对雄性幼虫期饮食与成年交配史进行了操控处理。研究结果显示，蛋白质限制组的雄性在年轻时期产生的后代存活力更低，但后代存活力会随父本年龄增长而提升，最终超过完全饲喂组雄性的后代存活力；雌性产卵数量不受雄性膳食蛋白质水平的影响，但卵孵化成功率（egg hatching success）受到雄性成年饮食、年龄、幼虫期饮食以及交配史的复杂交互作用调控。上述研究结果表明，蛋白质限制对雄性繁殖的效应具有极强的背景依赖性，无法通过“资源从繁殖活动向体细胞维持简单重新分配”这一单一机制解释，相反，这类效应似乎涉及雄性繁殖投入随年龄变化的时序调控。