DISSERTATION RESEARCH: The Role of Early Environment in the Development of a Lifelong Mate Choice Signal: Melanin- Based Color in Barn Swallows

论文研究：早期环境在终生择偶信号形成中的作用：家燕基于黑色素的颜色

• 批准号: 1601400
• 负责人: Rebecca Safran
• 金额: $ 1.99万
• 依托单位: University of Colorado at Boulder
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2016
• 资助国家: 美国
• 起止时间: 2016-05-01 至 2018-04-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1601400&HistoricalAwards=false
• 关键词: DISSERTATION; RESEARCH; Role; Early; Environment

Early life is a critical stage during which the environment experienced can have important life-long effects for an individual. Understanding how the interaction between an individual's genes and the environment during early development create the variation seen in nature is an important question in Biology. This research will leverage a well-established study system for evolutionary and behavioral research to determine how the developmental environment shapes the expression of a trait that is critical to reproductive success later in life. Specifically, this study will manipulate nest parasites, an important component of the environment, during early development to determine how parasite infections and the immune responses they generate interact with the genes that underlie plumage color in birds. Plumage color, here a brownish-red melanin coloration, is an important signal used in communication between the sexes and it is impacted by early life conditions, and therefore the reproductive success of an individual. Genes expressed in tissues where feathers are grown will be measured to allow for the identification of specific genes whose expression is influenced by environmental conditions. Results from this work will be broadly informative as melanin is a common pigment underlying appearance and coloration in various groups of animals. However, it is not well understood how the environment interacts with genes to influence the development of melanin coloration. Broader impacts include training undergraduates and middle-school teachers in scientific research, and the creation of lesson plans that will be implemented in public middle schools and shared broadly with teachers at science-teaching workshops.Female preferences for male coloration are thought to be adaptive because of the potential information advertised by these male traits. Melanin-based color traits are traditionally thought to be under strict genetic control. However, condition-dependence for some melanin traits may occur during early development. If so, trait variation may provide information about an individual's developmental history. Previous work has shown that variation in melanin-based color in barn swallows is due almost entirely (70%) to differences in early environment, and that plumage color provides information about ectoparasite loads in a male's territory. Mites affect nestling survival, growth, immunity, and melanin-based plumage color. This project will identify gene expression differences associated with color variation by cross-fostering eggs and manipulating mites to tease apart the roles of genes and environmental quality. Developing feathers will be collected and RNA expression will be quantified to understand how early environment interacts with genes in the melanin pathway to influence the life-long expression of a melanin-based signal. The research will have important implications for understanding the gene by environment interactions during the early developmental period for melanin-based ornamental traits, and thus, information that females gain by using these traits. Results from this work will provide a clearer picture of how melanin-based traits interact with the environment during development at many levels: from the detailed gene expression, to lifelong trait expression, to variation within a population and how this relates to the parasite community, and finally to divergent morphological traits across populations that are involved in reproductive isolation.

早期生活是一个关键阶段，在此期间，环境对个人产生重要的终身影响。了解早期发展过程中个人基因与环境之间的相互作用如何创造自然界中看到的差异是生物学的重要问题。这项研究将利用一个公认的研究系统进行进化和行为研究，以确定发展环境如何塑造对以后生命中生殖成功至关重要的特征的表达。具体而言，这项研究将在早期发育过程中操纵巢寄生虫，这是环境的重要组成部分，以确定寄生虫感染和它们产生的免疫反应如何与鸟类羽毛颜色的基因相互作用。羽毛色，这里是棕红色黑色素的颜色，是性别之间交流的重要信号，它受到早期生活条件的影响，因此受到个人的生殖成功。在生长羽毛的组织中表达的基因将被测量，以识别其表达受环境条件影响的特定基因。这项工作的结果将具有广泛的信息，因为黑色素是各组动物中的一种常见色素外观和着色。但是，尚不清楚环境如何与基因相互作用以影响黑色素颜色的发展。更广泛的影响包括培训本科生和中学教师科学研究，以及将在公立中学中实施的课程计划，并与科学教学研讨会上的教师广泛分享。男性色彩的偏好被认为是自适应的，因为这些男性traits宣传了这些男性特征的潜在信息。传统上认为基于黑色素的颜色特征是严格的遗传控制。但是，某些黑色素特征的状况依赖性可能会在早期发育过程中发生。如果是这样，特质的变化可能会提供有关个人发展历史的信息。先前的工作表明，谷仓燕子中基于黑色素的颜色的变化几乎完全归因于早期环境的差异（70％），并且羽毛颜色提供了有关男性领土上载脑岩载荷的信息。螨虫影响雏鸟存活，生长，免疫力和基于黑色素的羽毛色。该项目将通过交叉饲养卵和操纵螨虫来嘲笑基因和环境质量的作用来确定与颜色变化相关的基因表达差异。将收集发育的羽毛，并将量化RNA表达，以了解早期环境如何与黑色素途径中的基因相互作用，以影响基于黑色素的信号的终身表达。这项研究将对基于黑色素的观赏性状的早期发育时期内通过环境相互作用来理解基因的重要含义，因此，女性通过使用这些特征获得的信息。这项工作的结果将提供更清晰的图片，说明基于黑色素的特征如何在许多层面的发展过程中与环境相互作用：从详细的基因表达到终生特征表达，到人群内部的变化以及这与寄生虫群落之间的关系，最后与涉及生殖分离的人群之间的形态性质不同。