Institut Pluridisciplinaire Hubert Curien, Département Ecologie, Physiologie et Ethologie, CNRS-UDS, 23 rue Becquerel, Strasbourg Cedex 2, France.
Mol Ecol. 2012 Mar;21(6):1500-10. doi: 10.1111/j.1365-294X.2011.05331.x. Epub 2011 Nov 25.
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 damage levels and telomere length were measured at the beginning and at 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.
动物的生长速度不能达到潜在速度的原因之一是，快速生长已被证明与寿命缩短有关。然而，我们仍然缺乏对野生动物生长依赖性衰老机制调节的现实情况的清晰描述。利用小王企鹅雏鸟自然表现出高于正常生长速度的特定生长轨迹来弥补冬季中断，我们测试了氧化应激和端粒缩短是否与生长轨迹有关。在三个雏鸟组（小型雏鸟，即死亡或度过生长期的雏鸟，以及大型雏鸟）中，在冬季后生长期间的开始和结束时测量了血浆抗氧化防御、氧化损伤水平和端粒长度。在生长期间早期死亡的小型雏鸟在死亡前具有最高水平的氧化损伤和最短的端粒长度。在这里，我们表明，生长速度较快的小型雏鸟以牺牲身体维持机制为代价，这表现在（i）更高的氧化损伤和（ii）加速的端粒丢失。我们的研究首次提供了在自然条件下生长和衰老速度之间存在机制联系的证据。
