Data from: Interactions between parental traits, environmental harshness and growth rate in determining telomere length in wild juvenile salmon

A larger body size confers many benefits, such as increased reproductive success, ability to evade predators and increased competitive ability and social status. However, individuals rarely maximise their growth rates, suggesting that this carries costs. One such cost could be faster attrition of the telomeres that cap the ends of eukaryotic chromosomes and play an important role in chromosome protection. A relatively short telomere length is indicative of poor biological state, including poorer tissue and organ performance, reduced potential longevity and increased disease susceptibility. Telomere loss during growth may also be accelerated by environmental factors, but these have rarely been subjected to experimental manipulation in the natural environment. Using a wild system involving experimental manipulations of juvenile Atlantic salmon Salmo salar in Scottish streams, we found that telomere length in juvenile fish was influenced by parental traits and by direct environmental effects. We found that faster-growing fish had shorter telomeres and there was a greater cost (in terms of reduced telomere length) if the growth occurred in a harsher environment. We also found a positive association between offspring telomere length and the growth history of their fathers (but not mothers), represented by the number of years fathers had spent at sea. This suggests that there may be long term consequences of growth conditions and parental life history for individual longevity.

更大的体型可带来诸多益处，例如提升繁殖成功率、增强逃避天敌的能力、提升竞争实力与社会地位。然而，生物个体极少会最大化自身生长速率，这暗示该行为存在相应代价。其中一类代价可能是端粒（telomeres）的损耗加速：端粒是包裹真核染色体末端、对染色体保护发挥关键作用的结构。端粒长度相对较短预示着机体生理状态不佳，包括组织与器官功能下降、潜在寿命缩短以及疾病易感性升高。生长过程中的端粒丢失也可能受环境因素加速，但此类因素在自然环境中极少被开展实验操控。本研究依托苏格兰溪流中的野生大西洋鲑（Salmo salar）幼鱼开展实验操控，发现幼鱼的端粒长度受亲本性状与直接环境效应的共同影响。研究结果显示，生长速率更快的幼鱼端粒更短；若在更为严苛的环境中生长，则需付出更高的端粒长度缩减代价。此外，我们还发现子代端粒长度与父本（而非母本）的生长经历呈正相关，该生长经历以父本出海时长作为表征指标。这表明生长环境与亲本生活史或会对个体寿命产生长期影响。