Department of Ecology and Evolution, University of Lausanne, Lausanne, Switzerland.
Swiss Ornithological Institute, Sempach, Switzerland.
Heredity (Edinb). 2019 Sep;123(3):337-348. doi: 10.1038/s41437-019-0203-5. Epub 2019 Mar 5.
The hypothalamic-pituitary-adrenal (HPA) axis is responsible for the regulation of corticosterone, a hormone that is essential in the mediation of energy allocation and physiological stress. As a continuous source of challenge and stress for organisms, the environment has promoted the evolution of physiological adaptations and led to a great variation in corticosterone profiles within or among individuals, populations and species. In order to evolve via natural selection, corticosterone levels do not only depend on the strength of selection exerted on them, but also on the extent to which the regulation of corticosterone is heritable. Nevertheless, the heritability of corticosterone profiles in wild populations is still poorly understood. In this study, we estimated the heritability of baseline and stress-induced corticosterone levels in barn owl (Tyto alba) nestlings from 8 years of data, using a multivariate animal model based on a behavioural pedigree. We found that baseline and stress-induced corticosterone levels are strongly genetically correlated (r = 0.68-0.80) and that the heritability of stress-induced corticosterone levels (h = 0.24-0.33) was moderate and similar to the heritability of baseline corticosterone levels (h = 0.19-0.30). These findings suggest that the regulation of stress-induced corticosterone and baseline levels evolves at a similar pace when selection acts with the same intensity on both traits and that contrary to previous studies, the evolution of baseline and stress-induced level is interdependent in barn owls, as they may be strongly genetically correlated.
下丘脑-垂体-肾上腺 (HPA) 轴负责调节皮质酮，这是一种在能量分配和生理应激调节中至关重要的激素。作为生物体持续的挑战和压力源，环境促进了生理适应的进化，并导致个体、种群和物种之间皮质酮谱的巨大差异。为了通过自然选择进化，皮质酮水平不仅取决于对它们施加的选择强度，还取决于皮质酮调节的遗传程度。然而，野生种群中皮质酮谱的遗传仍知之甚少。在这项研究中，我们使用基于行为谱系的多变量动物模型，根据 8 年的数据，估计了仓鸮（Tyto alba）雏鸟基础和应激诱导皮质酮水平的遗传力。我们发现基础和应激诱导皮质酮水平具有很强的遗传相关性（r=0.68-0.80），应激诱导皮质酮水平的遗传力（h=0.24-0.33）适中，与基础皮质酮水平的遗传力（h=0.19-0.30）相似。这些发现表明，当选择对两种特征以相同强度作用时，应激诱导皮质酮和基础水平的调节以相似的速度进化，并且与之前的研究相反，仓鸮的基础和应激诱导水平的进化是相互依存的，因为它们可能具有很强的遗传相关性。
