发育过程中的次优条件可以缩短端粒,染色体末端的保护性DNA帽。较短的早期端粒长度(TL)可以表明减少的躯体维持,导致较低的生存率和较短的寿命。然而,尽管有明确的证据,并不是所有的研究都显示了生命早期的TL和生存或寿命之间的关系,这可能是由于生物学或研究设计的差异(例如,测量的生存期)。在精湛的仙女(Maluruscyaneus),我们评估了早期生命TL是否可以预测不同生活史阶段的死亡率(初出茅庐,少年,adult).然而,与对同类物的类似研究相反,早期生命TL不能预测该物种任何生命阶段的死亡率。然后,我们进行了一项荟萃分析,包括来自23项研究(15只鸟类和3种哺乳动物)的32种效应大小,以量化早期TL对死亡率的影响,同时考虑了生物学和方法学变异的潜在来源。总的来说,生命早期TL对死亡率的影响是显著的,对应于死亡率风险降低15%,TL每增加一个标准差。然而,校正发表偏倚时,效果变得更弱.与我们的预测相反,没有证据表明早期生命TL对死亡率的影响随物种寿命或测量存活时间的不同而不同.然而,早年TL对死亡风险的负面影响在一生中普遍存在.这些结果表明,早期TL对死亡率的影响更可能是环境依赖性的,而不是年龄依赖性的。虽然大量的权力和出版偏见问题突出了更多研究的必要性。
Suboptimal conditions during development can shorten telomeres, the protective DNA caps on the end of chromosomes. Shorter early-life telomere length (TL) can indicate reduced somatic maintenance, leading to lower survival and shorter lifespan. However, despite some clear evidence, not all studies show a relationship between early-life TL and survival or lifespan, which may be due to differences in biology or study design (e.g., survival period measured). In superb fairy-wrens (Malurus cyaneus), we assessed whether early-life TL predicts mortality across different life-history stages (fledgling,
juvenile, adult). However, in contrast to a similar study on a congener, early-life TL did not predict mortality across any life stage in this species. We then performed a meta-analysis including 32 effect sizes from 23 studies (15 birds and three mammals) to quantify the effect of early-life TL on mortality whilst taking into consideration potential sources of biological and methodological variation. Overall, the effect of early-life TL on mortality was significant, corresponding to a 15% reduction in mortality risk with each standard deviation increase in TL. However, the effect became weaker when correcting for publication bias. Contrary to our predictions, there was no evidence that effects of early-life TL on mortality varied with species lifespan or the period over which survival was measured. However, negative effects of early-life TL on mortality risk were pervasive throughout life. These results imply that effects of early-life TL on mortality are more likely to be context-dependent than age-dependent, although substantial power and publication bias issues highlight the need for more research.