Macroevolutionary Patterning in Glucocorticoids Suggests Different Selective Pressures Shape Baseline and Stress-Induced Levels
Macroevolutionary Patterning in Glucocorticoids Suggests Different Selective Pressures Shape Baseline and Stress-Induced Levels
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糖皮质激素的宏观进化模式表明不同的选择压力塑造基线和压力诱导水平
DOI：
10.1086/703112
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发表时间：
2019
期刊：
影响因子：
--
通讯作者：
Hau, Michaela
中科院分区：
文献类型：
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作者：
Vitousek, Maren N.;Johnson, Michele A.;Downs, Cynthia J.;Miller, Eliot T.;Martin, Lynn B.;Francis, Clinton D.;Donald, Jeremy W.;Fuxjager, Matthew J.;Goymann, Wolfgang;Hau, Michaela
糖皮质激素（GC）激素是脊椎动物重要的表型介质，但其循环浓度可显着变化。本文研究了四足动物GC水平的宏观进化模式，通过测试7个关于GC变化的特定假设，并评估这些假设是否揭示了GC进化的一致模式。如果选择通常倾向于GCs在有效应对挑战方面的“支持性”作用，那么在具有挑战性的环境中，基线和/或压力诱导的GCs可能更高。或者，如果选择通常倾向于“保护”不受gc引起的成本的影响，那么在挑战更普遍或更严重的环境中，gc可能会更低。基线GCs的预测指标都与支持效应一致：在较小的生物和那些生活在更需要能量的环境中的生物中，GCs的水平更高。在繁殖期间，终生繁殖机会较少的种群和物种的基线GCs也较高。相反，压力诱导的GCs的预测因素更符合保护假说：在繁殖期间，终生生殖机会较少的生物体的GCs水平较低。总的来说，这些模式表明，在广泛的分类尺度上，一些选择压力如何塑造gc具有惊人的一致性；同时，在具有挑战性的环境中，选择似乎以不同的方式作用于基线和应力诱导的gc。
Glucocorticoid (GC) hormones are important phenotypic mediators across vertebrates, but their circulating concentrations can vary markedly. Here we investigate macroevolutionary patterning in GC levels across tetrapods by testing seven specific hypotheses about GC variation and evaluating whether the supported hypotheses reveal consistent patterns in GC evolution. If selection generally favors the “supportive” role of GCs in responding effectively to challenges, then baseline and/or stress-induced GCs may be higher in challenging contexts. Alternatively, if selection generally favors “protection” from GC-induced costs, GCs may be lower in environments where challenges are more common or severe. The predictors of baseline GCs were all consistent with supportive effects: levels were higher in smaller organisms and in those inhabiting more energetically demanding environments. During breeding, baseline GCs were also higher in populations and species with fewer lifetime opportunities to reproduce. The predictors of stress-induced GCs were instead more consistent with the protection hypothesis: during breeding, levels were lower in organisms with fewer lifetime reproductive opportunities. Overall, these patterns indicate a surprising degree of consistency in how some selective pressures shape GCs across broad taxonomic scales; at the same time, in challenging environments selection appears to operate on baseline and stress-induced GCs in distinct ways.