Data from: Telomere elongation during early development is independent of environmental temperatures in Atlantic salmon

There is increasing evidence from endothermic vertebrates that telomeres, which cap the ends of chromosomes and play an important role in chromosome protection, decline in length during postnatal life and are a useful indicator of physiological state and expected lifespan. However, much less is currently known about telomere dynamics in ectothermic vertebrates, which are likely to differ from that of endotherms, at least in part due to the sensitivity of ectotherm physiology to environmental temperature. We report here on an experiment in which Atlantic salmon were reared through the embryonic and larval stages of development, and under differing temperatures, in order to examine the effects of environmental temperature during early life on telomere dynamics, oxidative DNA damage and cellular proliferation. Telomere length significantly increased between the embryonic and larval stages of development. Contrary to our expectations, variation in telomere length at the end of the larval stage was unrelated to either cell proliferation rate or the relative level of oxidative DNA damage, and did not vary between the temperature treatments. This study suggests that salmon are able to restore the length of their telomeres during early development, which may possibly help to buffer potentially harmful environmental effects experienced in early life.现有越来越多来自恒温脊椎动物（endothermic vertebrates）的研究证据表明：端粒（telomeres）作为覆盖染色体末端、在染色体保护中发挥关键作用的结构，会在出生后的生命进程中逐渐缩短，且可作为生理状态与预期寿命的有效指示指标。然而目前学界对变温脊椎动物（ectothermic vertebrates）的端粒动态变化的了解却相对匮乏，且这类动物的端粒动态很可能与恒温动物存在差异，这至少部分源于变温动物的生理机能对环境温度极为敏感。本研究报道了一项实验：我们将大西洋鲑鱼置于不同温度环境下，培育至其完成胚胎期与幼体期发育，以此探究生命早期环境温度对端粒动态变化、氧化DNA损伤（oxidative DNA damage）以及细胞增殖（cellular proliferation）的影响。研究发现，在胚胎期至幼体期的发育过程中，端粒长度显著增加。与我们的预期相悖的是，幼体期结束时的端粒长度变异，既与细胞增殖速率或氧化DNA损伤的相对水平无关，也未在不同温度处理组间呈现显著差异。本研究表明，鲑鱼可在早期发育阶段修复端粒长度，这或许有助于缓冲生命早期所遭遇的潜在有害环境影响。