School of Biological Sciences, University of East Anglia, Norwich Research Park, UK.
J Gerontol A Biol Sci Med Sci. 2020 Jul 13;75(8):1431-1438. doi: 10.1093/gerona/glz175.
Nutritional variation across the lifetime can have significant and sex-specific impacts on fitness. Using Drosophila melanogaster, we measured these impacts by testing the effects on life span and reproductive success of high or low yeast content in developmental versus adult diets, separately for each sex. We tested two hypotheses: that dietary mismatches between development and adulthood are costly and that any such costs are sex-specific. Overall, the results revealed the rich and complex responses of each sex to dietary variation across the lifetime. Contrary to the first hypothesis, dietary mismatches between developmental and adult life stages were not universally costly. Where costs of nutritional variation across the life course did occur, they were sex-, context-, and trait-specific, consistent with hypothesis 2. We found effects of mismatches between developmental and adult diets on reproductive success in females but not males. Adult diet was the main determinant of survival, and life span was significantly longer on high yeast adult food, in comparison to low, in both sexes. Developing on a high yeast diet also benefited adult female life span and reproductive success, regardless of adult diet. In contrast, a high yeast developmental diet was only beneficial for male life span when it was followed by low yeast adult food. Adult diet affected mating frequency in opposing directions, with males having higher mating frequency on high and females on low, with no interaction with developmental diet for either sex. The results emphasize the importance of sex differences and of the directionality of dietary mismatches in the responses to nutritional variation.
一生中营养的变化会对适应性产生显著的、具有性别特异性的影响。我们利用黑腹果蝇（Drosophila melanogaster），通过分别测试雄性和雌性在发育和成年期分别摄入高或低酵母含量的饮食对寿命和繁殖成功率的影响，来测量这些影响。我们检验了两个假设：一是发育和成年期饮食不匹配是有代价的，二是任何此类代价都是具有性别特异性的。总的来说，结果揭示了每个性别对一生中饮食变化的丰富而复杂的反应。与第一个假设相反，发育和成年期的饮食不匹配并不总是代价高昂的。在生命过程中营养变化的代价确实存在的情况下，它们是性别特异性、情境特异性和特征特异性的，与假设 2 一致。我们发现，发育和成年期饮食不匹配对雌性的繁殖成功率有影响，但对雄性没有影响。成年饮食是生存的主要决定因素，与低酵母饮食相比，高酵母成年饮食显著延长了两性的寿命。无论成年饮食如何，在高酵母饮食中发育也有益于成年雌性的寿命和繁殖成功率。相比之下，只有当雄性在高酵母饮食后再摄入低酵母成年饮食时，高酵母发育饮食才对雄性寿命有益。成年饮食以相反的方向影响交配频率，雄性在高酵母饮食下的交配频率更高，而雌性在低酵母饮食下的交配频率更高，无论性别，两者都与发育饮食没有相互作用。结果强调了性别差异和饮食不匹配的方向性在对营养变化的反应中的重要性。
