Department of Biology, Indiana University, Bloomington, IN, 47405, USA.
Department of Biology, Indiana University, Bloomington, IN, 47405, USA; Center for the Integrative Study of Animal Behavior, Indiana University, Bloomington, IN, 47405, USA.
Mol Cell Endocrinol. 2019 Oct 1;496:110531. doi: 10.1016/j.mce.2019.110531. Epub 2019 Jul 31.
Hormones have the potential to bring about rapid phenotypic change; however, they are highly conserved over millions of years of evolution. Here, we examine the evolution of hormone-mediated phenotypes, and the extent to which regulation is achieved via independence or integration of the many components of endocrine systems. We focus on the sex steroid testosterone (T), its cognate receptor (androgen receptor) and related endocrine components. We pose predictions about the mechanisms underlying phenotypic integration, including coordinated sensitivity to T within and among tissues and along the HPG axis. We then assess these predictions with case studies from wild birds, asking whether gene expression related to androgenic signaling naturally co-varies among individuals in ways that would promote phenotypic integration. Finally, we review how mechanisms of integration and independence vary over developmental or evolutionary time, and we find limited support for integration.
激素具有快速表型改变的潜力；然而，它们在数百万年的进化过程中高度保守。在这里，我们研究了激素介导的表型的进化，以及通过内分泌系统的许多成分的独立性或集成来实现调节的程度。我们专注于性类固醇睾丸激素（T）、其同源受体（雄激素受体）和相关的内分泌成分。我们对表型整合的潜在机制提出了预测，包括在组织内和组织间以及沿着 HPG 轴对 T 的协调敏感性。然后，我们用来自野生鸟类的案例研究来评估这些预测，询问与雄激素信号相关的基因表达是否会以促进表型整合的方式在个体之间自然变化。最后，我们回顾了整合和独立性的机制如何随时间而变化，我们发现整合的支持有限。
