Data from: Catching-up but telomere loss: half-opening the black box of growth and ageing trade-off in wild king penguin chicks

One of the reasons for animals not to grow as fast as they potentially could is that fast growth has been shown to be associated with reduced lifespan. However, we are still lacking a clear description of the reality of growth-dependent modulation of ageing mechanisms in wild animals. Using the particular growth trajectory of small king penguin chicks naturally exhibiting higher-than-normal growth rate to compensate for the winter break, we tested whether oxidative stress and telomere shortening are related to growth trajectories. Plasma antioxidant defences, oxidative damages levels and telomere length were measured at the beginning and the end of the post-winter growth period in three groups of chicks (small chicks which either passed away or survived the growth period, and large chicks). Small chicks that died early during the growth period had the highest level of oxidative damage and the shortest telomere lengths prior to death. Here, we show that small chicks that grew faster did it at the detriment of body maintenance mechanisms as shown by (i) higher oxidative damage and (ii) accelerated telomere loss. Our study provides the first evidence for a mechanistic link between growth and ageing rates under natural conditions.动物无法按照其潜在生长速率发育的核心原因之一，是已有研究证实快速生长与寿命缩短存在显著关联。然而，当前学界仍缺乏针对野生动物中生长依赖型衰老调控机制的清晰阐释。本研究以小体型王企鹅(king penguin)幼雏为研究对象——这类幼雏天然具备高于常规水平的生长速率，以弥补冬季断食期的影响——我们检验了氧化应激(oxidative stress)与端粒缩短(telomere shortening)是否与个体生长轨迹存在关联。研究人员在冬后生长期(post-winter growth period)的起始与结束阶段，对三组幼雏分别展开检测：生长周期内夭折的小型幼雏、存活的小型幼雏，以及大型幼雏，检测指标包括血浆抗氧化防御系统(plasma antioxidant defences)、氧化损伤水平(oxidative damages levels)与端粒长度(telomere length)。结果显示，生长早期夭折的小型幼雏，其死亡前的氧化损伤水平最高，端粒长度也最短。本研究证实，生长速度更快的小型幼雏，其机体维持机制会受到损害，具体表现为：(i) 氧化损伤水平显著升高；(ii) 端粒丢失进程加速。本研究首次在自然环境下，为生长速率与衰老速度之间的机制性关联提供了直接实证依据。