Department of Animal and Plant Sciences & Bateson Centre, The University of Sheffield, Sheffield S10 2TN, UK.
Department of Animal and Plant Sciences & Bateson Centre, The University of Sheffield, Sheffield S10 2TN, UK
J Exp Biol. 2020 Dec 2;223(Pt 23):jeb230185. doi: 10.1242/jeb.230185.
Dietary restriction (DR) is a key focus in ageing research. Specific conditions and genotypes were recently found to negate lifespan extension by DR, questioning its universal relevance. However, the concept of dietary reaction norms explains why the effects of DR might be obscured in some situations. We tested the importance of dietary reaction norms by measuring longevity and fecundity on five diets in five genotypes, with and without water supplementation in female (>25,000). We found substantial genetic variation in the response of lifespan to diet. Flies supplemented with water rescued putative desiccation stress on the richest diets, suggesting that water availability can be an experimental confound. Fecundity declined on these richest diets, but was unaffected by water, and this reduction is thus most likely to be caused by nutritional toxicity. Our results demonstrate empirically that a range of diets need to be considered to conclude an absence of the DR longevity effect.
饮食限制（DR）是衰老研究的一个重点。最近发现，特定的条件和基因型可以否定 DR 对寿命的延长作用，这对其普遍性提出了质疑。然而，饮食反应规范的概念解释了为什么在某些情况下 DR 的效果可能会被掩盖。我们通过在五种基因型的雌性个体中（>25,000 只），在有和没有水补充的情况下，用五种饮食进行测量，来检验饮食反应规范的重要性，以测量寿命和繁殖力。我们发现，饮食对寿命的反应存在很大的遗传变异。补充水的果蝇可以挽救在最丰富的饮食中可能出现的脱水应激，这表明水的可用性可能是一个实验混淆因素。在这些最丰富的饮食中，繁殖力下降，但不受水的影响，因此这种减少很可能是由营养毒性引起的。我们的研究结果从经验上证明，需要考虑一系列的饮食来得出 DR 对寿命延长效应不存在的结论。
