Brood size is associated with apparent telomere lengthening in nestling barn swallows
Brood size is associated with apparent telomere lengthening in nestling barn swallows
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DOI：
10.1007/s00442-023-05375-0
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发表时间：
2023-04-23
期刊：
影响因子：
2.7
通讯作者：
Levin，Iris I.
中科院分区：
文献类型：
--
作者：
Voirin，Charlie J.;Tsunekage，Toshi;Levin，Iris I.
动物的早期生活通常是快速生长和发育的时期。在资源有限的环境中，生活史理论预测，必须在资源汇之间进行权衡，以优化未来的生存和繁殖成功。端粒已经成为这些早期生命权衡的假定指标，但关于发育特征和条件如何影响端粒长度和动态，存在相互矛盾的说法。2年来，我们研究了雏鸟的繁殖人口的谷仓燕子从第6天到第12天的生活，测量各种个体发育因素，以了解他们在多大程度上解释端粒长度和动态的变化。我们意外地发现端粒在两个采样点之间变长了。大窝中的雏鸟端粒较短，但令人惊讶的是，从第6天到第12天生长较快的个体端粒较长，端粒延长更多。在第6天，相对于他们的同伴，质量较高的雏鸟的端粒较短，这表明家燕在发育早期经历的相对快速的生长比发育后期相对较慢的生长成本更高。这些影响仅在研究的第一年发现。端粒延长可能是由于在发育过程中新造血细胞系的启动或生命早期端粒酶的表达。有利的早期生活条件和高亲本投资可以允许更多的生长，而对端粒长度或动力学几乎没有成本。
Early life for animals is often a time of rapid growth and development. In a resource-limited environment, life history theory predicts that there must be trade-offs between resource sinks in ways that optimize future survival and reproductive success. Telomeres have emerged as putative indicators of these early life trade-offs, but there are conflicting accounts as to how developmental traits and conditions impact telomere length and dynamics. For 2 years, we studied the nestlings of a breeding population of barn swallows from day 6 to day 12 of life, measuring various ontogenetic factors to understand to what extent they explain variation in telomere length and dynamics. We unexpectedly found that telomeres lengthened between the two sampling points. Nestlings in large broods had shorter telomeres, but surprisingly, individuals that grew faster from day 6 to day 12 had longer telomeres and more telomere lengthening. Nestlings with higher mass relative to their nestmates on d6 had shorter telomeres, suggesting that the relatively fast growth barn swallows experience early in development is more costly than the relatively slower growth later in development. These effects were only found in the first year of study. Telomere lengthening may be due to the initiation of new hematopoietic cell lines during development or the expression of telomerase early in life. Favorable early life conditions and high parental investment could allow for more growth with little to no cost to telomere length or dynamics.