Drake Elizabeth D, Simons Mirre J P
School of Biosciences, University of Sheffield, Sheffield, United Kingdom.
Institute of Ecology and Evolution, Ashworth Laboratories, The King's Buildings, The University of Edinburgh, Edinburgh, United Kingdom.
Aging Biol. 2023 Aug 4;1(1):20230012. doi: 10.59368/agingbio.20230012.
Stochastic effects are central to the biology and demography of aging. Genetically identical individuals do not all die at the exact same time but show a distribution of lifespan. Although such effects are appreciated, any cascading effects from the stochastic effects of aging are underappreciated. We show here that genetically identical female flies () that live long produce longer-lived daughters. In line with previous work, we also find that daughters born to older mothers are shorter-lived, also termed the Lansing effect. We further show that longer-lived flies produce less offspring, suggesting an apparent trade-off due to stochastic effects alone. We explain these effects using an extension of the reliability theory of aging by dichotomizing aging physiology in reproduction and lifespan-supporting units. These simple models reproduce the nongenetic inheritance of lifespan, the Lansing effect, and trade-offs between reproduction and lifespan. Our work implies that if nongenetic inheritance of lifespan is widespread, it explains the generally low heritability of this trait. Furthermore, trade-offs between performance, for example, reproduction, and lifespan may be less widespread than predicted by the evolutionary biology of aging, stemming from stochasticity rather than differential investment. Antiaging treatments could therefore come without any unintended costs to other physiology, a perceived risk that limits the translation of these treatments to humans.
随机效应是衰老生物学和人口统计学的核心。基因相同的个体并非都在同一时刻死亡，而是呈现出寿命分布。尽管人们认识到了这些效应，但衰老随机效应产生的任何级联效应却未得到充分认识。我们在此表明，寿命长的基因相同的雌性果蝇会生出寿命更长的女儿。与之前的研究一致，我们还发现，老年雌蝇所生的女儿寿命较短，这也被称为兰辛效应。我们进一步表明，寿命长的果蝇产生的后代较少，这表明仅由于随机效应就存在明显的权衡取舍。我们通过将衰老生理学在生殖和寿命维持单元中进行二分，对衰老可靠性理论进行扩展来解释这些效应。这些简单模型再现了寿命的非遗传继承、兰辛效应以及生殖与寿命之间的权衡取舍。我们的研究表明，如果寿命的非遗传继承广泛存在，那么这就解释了该性状普遍较低的遗传力。此外，性能（例如生殖）与寿命之间的权衡取舍可能没有衰老进化生物学预测的那么普遍，这源于随机性而非差异投资。因此，抗衰老治疗可能不会给其他生理功能带来任何意外成本，而这一可感知的风险限制了这些治疗方法向人类的转化。
