DISSERTATION RESEARCH: Hormonal Regulation of Feather Color Development and Variation across Populations

鸟类的羽毛是地球上最引人注目的多样性例子之一。羽毛的颜色和形状在鸟类求偶仪式、伪装和其他社会和生态互动中至关重要。羽毛可以快速进化--同一物种的种群在羽毛颜色和图案上往往表现出显著的差异。然而，造成这些差异的机制却鲜为人知。Abolins-Abols研究了个体和种群之间羽毛颜色的不同方式和原因。在这篇论文中，改进项目Abolins-Abols将研究调节黑眼Junco多个种群两种快速进化的羽毛特征-头部和尾部颜色-发展的荷尔蒙机制。Dark-Eyes Junco是一种小型鸣鸟，经常造访美国各地的喂食者。这项研究将增加我们对鸟类颜色多样性进化的理解，因为头部和尾部的羽毛是鸣禽之间变异的热点。该项目还将培训本科生，并利用新建立的鸟类环志站促进与普通公众的接触，Abolins-Abols将在那里描述各种候鸟物种的颜色变化。这种研究系统的可负担性和简单性使其成为未来发展和进化研究项目的首选，特别是在文科大学等较小的机构。一些羽毛饰品被用作诚实的信号，表明它们的发育与行为等其他表型特征相结合。这种整合的一个候选机制是荷尔蒙，它同时调节神经和外周过程。虽然激素已经被证明是调节性别差异颜色的媒介，但我们还不知道激素在调节羽毛颜色的个体差异和种群差异中所起的作用。Abolins-Abols建议研究遗传和荷尔蒙机制，这些机制调节着两种快速进化的社会羽毛装饰物的发展--黑眼Juncos的头和尾的颜色--跨越不同颜色的种群。这些诚实的羽毛装饰品被证明与睾丸激素生理上的个体差异有关，这表明荷尔蒙和羽毛颜色之间存在因果联系。为了清楚地了解激素是否以及如何调节这种变异，Abolins-Abols将结合睾丸激素和黄体生成素的实验操作，分析发育羽毛中激素受体基因和蛋白质的表达。通过了解这些装饰品的荷尔蒙调节，我们将深入了解这些装饰品是如何与行为联系在一起的，以及更好地理解荷尔蒙如何调节社会羽毛装饰品的差异。

Bird feathers are one of the most striking examples of diversity on the planet. The color and shape of feathers are of fundamental importance in bird courtship rituals, camouflage, and other social and ecological interactions. Feathers can evolve rapidly - populations of the same species often show striking differences in feather color and patterns. The mechanisms that are responsible for these differences, however, are poorly understood. Abolins-Abols investigates how and why feather color differs between individuals and populations. In this dissertation improvement project Abolins-Abols will investigate the hormonal mechanisms that regulate the development of two rapidly evolving feather traits - head and tail color - across multiple populations of the Dark-eyed Junco, a small songbird that is a common visitor to feeders across the United States. This research will increase our understanding of the evolution of bird color diversity, because head and tail feathers are hotspots for variation across songbirds. This project will also train undergraduate students and facilitate outreach to the general public using the newly founded bird banding station where Abolins-Abols will characterize color variation across a variety of migratory bird species. The affordability and simplicity of this study system make it a prime candidate for future research programs in development and evolution, especially at smaller institutions such as liberal arts colleges.Some feather ornaments are used as honest signals, suggesting that their development is integrated with other phenotypic traits such as behavior. A candidate mechanism for this integration is hormones, which regulate both neural and peripheral processes. While hormones have been shown to mediate sex differences coloration, we do not yet understand the role of hormones in mediating individual differences and population divergence in feather color. Abolins-Abols proposes to investigate the genetic and hormonal mechanisms that mediate the development of two rapidly evolving social plumage ornaments - head and tail color in Dark-eyed Juncos - across populations of varying coloration. These honest feather ornaments have been shown to be related to individual differences in testosterone physiology, suggesting a causal link between hormones and feather color. To gain an explicit understanding of whether and how hormones regulate this variation, Abolins-Abols will analyze hormone receptor gene and protein expression in developing feathers in combination with experimental manipulations of testosterone and luteinizing hormone. By understanding the hormonal regulation of these ornaments we will gain insight into how these ornaments are linked to behavior as well as a better understanding of how hormones mediate the divergence of social feather ornaments.