Phenotypic integration and independence: Hormones, performance, and response to environmental change
Phenotypic integration and independence: Hormones, performance, and response to environmental change
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DOI：
10.1093/icb/icp057
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发表时间：
2009-10-01
影响因子：
2.6
通讯作者：
McGlothlin, Joel W.
中科院分区：
文献类型：
--
作者：
Ketterson, Ellen D.;Atwell, Jonathan W.;McGlothlin, Joel W.
激素协调行为，生理和形态特征的共同表达，引起特征和生物体之间的相关性，这些生物体的各部分可以很好地协同工作。本文认为，这些激素的相关性的影响，相对于进化的激素介导的性状。这些性状可以由于激素分泌、激素对载体蛋白的亲和力、降解和转化速率以及与靶组织的相互作用的变化而进化。然而，至关重要的是，我们对这些变化是独立发生还是串联发生知之甚少，因此激素是否促进紧密表型整合的进化或容易允许表型的部分独立进化。例如，当选择倾向于改变生殖介导性状的表达时，这种改变可能是通过激素分泌的变化（信号强度），对固定水平分泌的反应变化（靶组织的敏感性），还是两者兼而有之？在一个极端，如果表型是紧密整合的，并且只有信号通过选择对一个或多个细胞介导的性状的作用而响应，则适应性修饰可能受到过去选择的限制。或者，如果多变量选择倾向于可以通过信号强度的变化容易地实现的新组合，则可以促进对选择的响应。另一方面，如果个体靶组织很容易从激素信号中“拔出”以响应选择，那么表型可以被视为一个松散的邦联，在逐个性状的基础上做出反应，很容易允许适应性修改，尽管可能比信号变化是进化反应的主要模式要慢。这里回顾的研究和未来研究的问题，通过比较性别，个人和人群解决整合和独立的相对重要性。大多数注意力都集中在激素睾酮（T）和一种鸣禽物种，黑眼junco（Junco hyemalis）。
Hormones coordinate the co-expression of behavioral, physiological, and morphological traits, giving rise to correlations among traits and organisms whose parts work well together. This article considers the implications of these hormonal correlations with respect to the evolution of hormone-mediated traits. Such traits can evolve owing to changes in hormone secretion, hormonal affinity for carrier proteins, rates of degradation and conversion, and interaction with target tissues to name a few. Critically, however, we know very little about whether these changes occur independently or in tandem, and thus whether hormones promote the evolution of tight phenotypic integration or readily allow the parts of the phenotype to evolve independently. For example, when selection favors a change in expression of hormonally mediated characters, is that alteration likely to come about through changes in hormone secretion (signal strength), changes in response to a fixed level of secretion (sensitivity of target tissues), or both ? At one extreme, if the phenotype is tightly integrated and only the signal responds via selection's action on one or more hormonally mediated traits, adaptive modification may be constrained by past selection for phenotypic integration. Alternatively, response to selection may be facilitated if multivariate selection favors new combinations that can be easily achieved by a change in signal strength. On the other hand, if individual target tissues readily "unplug" from a hormone signal in response to selection, then the phenotype may be seen as a loose confederation that responds on a trait-by-trait basis, easily allowing adaptive modification, although perhaps more slowly than if signal variation were the primary mode of evolutionary response. Studies reviewed here and questions for future research address the relative importance of integration and independence by comparing sexes, individuals, and populations. Most attention is devoted to the hormone testosterone (T) and a songbird species, the dark-eyed junco (Junco hyemalis).