Reichert Sophie, Criscuolo François, Zahn Sandrine, Arrivé Mathilde, Bize Pierre, Massemin Sylvie
Université de Strasbourg, Institut Pluridisciplinaire Hubert Curien, Département Ecologie, Physiologie et Ethologie, 23 Rue Becquerel, 67087 Strasbourg Cedex 2, France CNRS, UMR 7178, 67087 Strasbourg Cedex 2, France
Université de Strasbourg, Institut Pluridisciplinaire Hubert Curien, Département Ecologie, Physiologie et Ethologie, 23 Rue Becquerel, 67087 Strasbourg Cedex 2, France CNRS, UMR 7178, 67087 Strasbourg Cedex 2, France.
J Exp Biol. 2015 Feb 1;218(Pt 3):491-9. doi: 10.1242/jeb.109942. Epub 2014 Dec 18.
Conditions experienced during development and growth are of crucial importance as they can have a significant influence on the optimisation of life histories. Indeed, the ability of an organism to grow fast and achieve a large body size often confers short- and long-term fitness benefits. However, there is good evidence that organisms do not grow at their maximal rates as growth rates seem to have potential costs on subsequent lifespan. There are several potential proximate causes of such a reduced lifespan. Among them, one emerging hypothesis is that growth impacts adult survival and/or longevity through a shared, end point, ageing mechanism: telomere erosion. In this study, we manipulated brood size in order to investigate whether rapid growth (chicks in reduced broods) is effectively done at the cost of a short- (end of growth) and long-term (at adulthood) increase of oxidative damage and telomere loss. Contrary to what we expected, chicks from the enlarged broods displayed more oxidative damage and had shorter telomeres at the end of the growth period and at adulthood. Our study extends the understanding of the proximate mechanisms involved in the trade-off between growth and ageing. It highlights that adverse environmental conditions during growth can come at a cost via transient increased oxidative stress and pervasive eroded telomeres. Indeed, it suggests that telomeres are not only controlled by intrinsic growth rates per se but also may be under the control of some extrinsic environmental factors, which could complicate our understanding of the growth-ageing interaction.
发育和成长过程中所经历的条件至关重要，因为它们会对生活史的优化产生重大影响。实际上，生物体快速生长并达到较大体型的能力通常会带来短期和长期的适应性益处。然而，有充分证据表明生物体并非以最大速率生长，因为生长速率似乎会对后续寿命产生潜在代价。寿命缩短有几个潜在的直接原因。其中，一个新出现的假说是，生长通过一种共同的终点衰老机制——端粒侵蚀，影响成年个体的生存和/或寿命。在本研究中，我们操纵窝雏数，以调查快速生长（来自较小窝雏的雏鸟）是否确实是以短期（生长结束时）和长期（成年时）氧化损伤增加和端粒丢失为代价的。与我们的预期相反，来自较大窝雏的雏鸟在生长末期和成年时表现出更多的氧化损伤且端粒更短。我们的研究扩展了对生长与衰老之间权衡所涉及的直接机制的理解。它强调生长期间的不利环境条件可能会通过短暂增加的氧化应激和普遍侵蚀的端粒而付出代价。实际上，这表明端粒不仅受内在生长速率本身的控制，还可能受某些外在环境因素的控制，这可能会使我们对生长 - 衰老相互作用的理解变得复杂。
