Data from: The nutritional geometry of parental effects: maternal and paternal macronutrient consumption and offspring phenotype in a neriid fly

Although the ecological and evolutionary importance of environmentally induced parental effects is now widely recognized, such effects are still typically studied by contrasting just two environments in a single parental sex. Yet, parental effects should generally be viewed as reaction norms, and a more complete understanding of their ecological role therefore requires examining continuously varying and interacting environmental variables in both parental sexes.
We used nutritional geometry to investigate linear, nonlinear and interactive effects of protein and carbohydrate in maternal and paternal larval diets on offspring juvenile development and viability and adult body size and shape in the fly Telostylinus angusticollis (Diptera: Neriidae).
We found that egg hatching success was enhanced by protein in the maternal larval diet but reduced by protein in the paternal larval diet, while other juvenile traits were unaffected by parental diets.
Maternal effects on offspring adult body size and head elongation (a secondary sexual trait in males) were mediated by linear and quadratic effects of protein, and were consistent in sons and daughters. In contrast, paternal effects on offspring body size and head elongation were mediated by carbohydrate effects or carbohydrate─protein interactions, and varied by offspring sex.
Our findings show that macronutrients in the parental larval diet can have complex, nonlinear and interactive effects on offspring traits, and that the effects of maternal and paternal diets can be strikingly different. Effects of parental diet on offspring represent important fitness consequences of variation in nutrient intake, with potential implications for the evolution of foraging and reproductive strategies.

尽管环境诱导的亲本效应（environmentally induced parental effects）在生态学与进化领域的重要性已获广泛认可，但此类效应的现有研究通常仅针对单一亲本性别，通过对比两种环境条件开展。然而，亲本效应本质上应被视作反应规范（reaction norms），因此要全面阐明其生态学作用，需同时针对双亲性别，探究连续变化且存在交互作用的环境变量的影响。
本研究采用营养几何学（nutritional geometry）方法，以窄茎蝇（Telostylinus angusticollis，双翅目：大跗蝇科）为实验对象，探究亲本（母本与父本）幼虫日粮中蛋白质与碳水化合物的线性、非线性及交互效应对后代幼体发育、存活率以及成体体型与形态的影响。
研究结果显示，母本幼虫日粮中的蛋白质可提升卵孵化成功率，而父本幼虫日粮中的蛋白质则会降低卵孵化成功率，其余幼体性状均不受亲本日粮的影响。
母本日粮对后代成体体型及头部伸长（雄性次要性征（secondary sexual trait））的效应由蛋白质的线性与二次效应介导，且在子代雌雄个体中表现一致。与之相反，父本日粮对后代体型与头部伸长的效应则由碳水化合物效应或碳水化合物-蛋白质交互作用介导，且因子代性别不同而存在差异。
本研究结果表明，亲本幼虫日粮中的大量营养素（macronutrients）可对后代性状产生复杂、非线性且存在交互作用的影响，且母本与父本日粮的效应存在显著差异。亲本日粮对后代的效应，反映了营养摄入变异对适合度（fitness）的重要影响，这可能对觅食与繁殖策略的进化具有潜在意义。