Is telomere length a molecular marker of past thermal stress in wild fish?
Is telomere length a molecular marker of past thermal stress in wild fish?
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DOI：
10.1111/mec.13856
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发表时间：
2016-11-01
影响因子：
4.9
通讯作者：
Vasemagi, Anti
中科院分区：
文献类型：
--
作者：
Debes, Paul V.;Visse, Marko;Vasemagi, Anti
端粒保护真核染色体；端粒长度的变化（主要在恒温动物中）与压力、细胞衰老和疾病风险的变化有关。此外，端粒被认为可以作为量化过去环境压力的生物标志物，但对野生动物的研究仍然很少。环境压力，例如变温动物的极端环境温度，可能会导致氧化应激，加速端粒磨损。然而，生长可能取决于温度，也会导致端粒磨损。为了测试多组织端粒长度与过去水温之间的关联，同时考虑到之前的个体生长情况，我们使用定量 PCR 分析了来自 10 条天然河流的 112 条当年幼褐鳟鱼的样本，这些河流的平均水温差异高达 6 摄氏度（绝对最大值为 23 摄氏度）。我们发现相对端粒长度（RTL）与平均河流温度和个体体型之间存在负相关。我们没有发现六种组织之间 RTL 与温度关联存在差异的迹象，但我们确实发现了组织之间 RTL 与体型之间关联存在差异的迹象；体型趋势虽然差异不显着，但肌肉最强，鳍最弱。尽管温度、生长、氧化应激和横截面端粒长度之间的因果关系仍然很大程度上未知，但我们的结果表明变温野生动物的端粒长度变化与过去的温度和生长有关。
Telomeres protect eukaryotic chromosomes; variation in telomere length has been linked (primarily in homoeothermic animals) to variation in stress, cellular ageing and disease risk. Moreover, telomeres have been suggested to function as biomarker for quantifying past environmental stress, but studies in wild animals remain rare. Environmental stress, such as extreme environmental temperatures in poikilothermic animals, may result in oxidative stress that accelerates telomere attrition. However, growth, which may depend on temperature, can also contribute to telomere attrition. To test for associations between multitissue telomere length and past water temperature while accounting for the previous individual growth, we used quantitative PCR to analyse samples from 112 young-of-the-year brown trout from 10 natural rivers with average water temperature differences of up to 6 degrees C (and an absolute maximum of 23 degrees C). We found negative associations between relative telomere length (RTL) and both average river temperature and individual body size. We found no indication of RTL-temperature association differences among six tissues, but we did find indications for differences among the tissues for associations between RTL and body size; size trends, albeit nonsignificant in their differences, were strongest in muscle and weakest in fin. Although causal relationships among temperature, growth, oxidative stress, and cross-sectional telomere length remain largely unknown, our results indicate that telomere-length variation in a poikilothermic wild animal is associated with both past temperature and growth.