The mechanisms connecting environmental conditions to plasticity in biological aging trajectories are fundamental to understanding individual variation in functional traits and life history. Recent findings suggest that telomere biology is especially dynamic during early life stages and has long-term consequences for subsequent reproduction and survival. However, our current understanding is mostly derived from studies investigating ecological and anthropogenic factors separately, leaving the effects of complex environmental interactions unresolved. American alligators (Alligator mississippiensis) are long-lived apex predators that rely on incubation temperature during a discrete period during development and endocrine cues to determine sex, making them especially vulnerable to current climatic variability and exposure to anthropogenic contaminants interfering with hormone function. Here, we combine field studies with a factorial design to understand how the developmental environment, along with intrinsic biological variation contribute to persistent telomere variation. We found that exposure to a common endocrine disrupting contaminant, DDE, affects telomere length, but that the directionality is highly dependent upon incubation temperature. Variation in hatchling growth, underlies a strong clutch effect. We also assess concentrations of a panel of glucocorticoid hormones and find that contaminant exposure elicits an increase in circulating glucocorticoids. Consistent with emerging evidence linking stress and aging trajectories, GC levels also appear to trend with shorter telomere length. Thus, we add support for a mechanistic link between contaminants and glucocorticoid signalling, which interacts with ecological aspects of the developmental environment to alter telomere dynamics.

中文翻译：

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内在和外在因素在发育过程中相互作用以影响长寿爬行动物的端粒长度

将环境条件与生物衰老轨迹的可塑性联系起来的机制对于理解功能特征和生活史的个体差异至关重要。最近的研究结果表明，端粒生物学在生命早期阶段尤其活跃，并对随后的繁殖和生存产生长期影响。然而，我们目前的理解主要来自于分别调查生态和人为因素的研究，而复杂的环境相互作用的影响尚未得到解决。美洲短吻鳄 ( Alligator mississippiensis) 是长寿的顶级捕食者，它们在发育过程中的一个离散时期依赖孵化温度和内分泌线索来确定性别，这使得它们特别容易受到当前气候变化和暴露于干扰激素功能的人为污染物的影响。在这里，我们将实地研究与析因设计相结合，以了解发育环境以及内在生物变异如何导致持续的端粒变异。我们发现暴露于常见的内分泌干扰污染物 DDE 会影响端粒长度，但方向性在很大程度上取决于培养温度。孵化生长的变化是强大的离合效应的基础。我们还评估了一组糖皮质激素的浓度，发现接触污染物会导致循环糖皮质激素增加。与将压力和衰老轨迹联系起来的新证据一致，GC 水平似乎也随着端粒长度的缩短而变化。因此，我们增加了对污染物和糖皮质激素信号之间的机制联系的支持，后者与发育环境的生态方面相互作用以改变端粒动力学。