Dietary Restriction Improves Fitness of Aging Parents But Reduces Fitness of Their Offspring in Nematodes

Abstract Dietary restriction (DR) is a well-established intervention to extend lifespan across taxa. Recent studies suggest that DR-driven lifespan extension can be cost-free, calling into question a central tenant of the evolutionary theory of aging. Nevertheless, boosting parental longevity can reduce offspring fitness. Such intergenerational trade-offs are often ignored but can account for the “missing costs” of longevity. Here, we use the nematode Caenorhabditis remanei to test for effects of DR by fasting on fitness of females and their offspring. Females deprived of food for 6 days indeed had increased fecundity, survival, and stress resistance after re-exposure to food compared with their counterparts with constant food access. However, offspring of DR mothers had reduced early and lifetime fecundity, slower growth rate, and smaller body size at sexual maturity. These findings support the direct trade-off between investment in soma and gametes challenging the hypot...摘要 膳食限制（Dietary restriction, DR）是已被广泛证实可跨类群延长生物体寿命的干预手段。近期研究表明，DR介导的寿命延长或许无需付出代价，这对衰老进化理论的核心信条提出了质疑。然而，提升亲本寿命会降低子代的适合度。这类常被忽视的代际权衡，或可解释长寿的“缺失成本”。本研究以雷氏隐杆线虫（Caenorhabditis remanei）为实验材料，通过禁食实施DR，探究其对雌性亲本及其子代适合度的影响。结果显示，与持续获得食物的对照雌性相比，禁食6天的雌性在重新摄食后，其繁殖力、寿命及抗逆性均显著提升。但经DR处理的亲本所产子代，其早期繁殖力与终生繁殖力均下降、生长速率减慢，且性成熟时体型更小。上述研究结果支持了体细胞与生殖细胞投资间存在直接权衡的假说，对……提出了挑战