Shifting Adaptations: Genomics of Adaptation and Speciation with Gene Flow

适应转变：适应和物种形成的基因组学与基因流

• 批准号: RGPIN-2018-05251
• 负责人: Friesen, Victoria
• 金额: $ 4.01万
• 依托单位: Queen's University
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2019
• 资助国家: 加拿大
• 起止时间: 2019-01-01 至 2020-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=690620
• 关键词: Shifting; Adaptations; Genomics; Adaptation; Speciation

New theoretical models and increasingly powerful methods for unlocking the evolutionary information contained in genomes are challenging the classical models of adaptation and speciation. Traditionally, the potential for populations to adapt to the local environment was thought to depend primarily on selection, genetic variation, gene flow and genetic drift. However, recent research suggests that the potential for local adaptation depends on two additional critical factors: 1) the source of genetic variation (new mutations versus “standing genetic variation”- variation that already exists in a population); and 2) “genomic architecture” (the number of genes controlling a trait, and the physical and functional relationships among them). The interactions among gene flow, genomic architecture and adaptation are complex in theory, and largely unexplored in natural populations. In the present application, I propose to use a novel combination of whole genome sequencing and targeted gene sequencing to test the effect of gene flow on standing genetic variation and genomic architecture during local adaptation and speciation. My proposed program has two themes, using seabirds as model systems:******Theme I will test the role of standing variation in adaptation and speciation by allochrony - differences in breeding time. In several archipelagos worldwide, morphologically different conspecific populations of storm-petrels (Hydrobates spp.) breed in the same colonies in warm versus cool seasons. We will test the hypothesis that seasonal adaptations on different archipelagoes arose from standing genetic variation, as opposed to independent mutations or recent gene flow between archipelagoes. We will also test the hypothesis that genomic architecture changes during the divergence process.******Theme II tests the contribution of inter-species gene flow to adaptation in peripheral populations. Specifically, we will test whether 1) adaptive introgression from ground-nesting Kittlitz's murrelets (Brachyramphus brevirostris) enabled tree-nesting marbled murrelets (B. marmoratus) to expand their range into treeless areas; and 2) speciation in white-headed gulls (Larus spp.) entailed repeated isolation and secondary contact (gene flow) between ancestral populations during the Pleistocene glaciations.******Understanding the effects of gene flow on standing variation and genomic architecture during adaptation is arguably one of the most important gaps in our understanding of evolution, since it affects all aspects of biological organization from behaviour through population dynamics to speciation. It also is integral to our ability to predict, and hopefully mitigate, the effects of anthropogenic change on biodiversity. The proposed work will provide training in genomics, bioinformatics, and field ecology for 3 PhD, 2 MSc and 10 BSc students.***

新的理论模型和越来越强大的方法解锁基因组中包含的进化信息的方法受到挑战的经典适应模型和特定模型。传统上，人们认为种群适应当地环境的潜力主要取决于选择，遗传变异，基因流和遗传漂移。然而，最近的研究表明，局部适应的潜力取决于两个其他关键因素：1）遗传变异的来源（新突变与“遗传差异” - 人群中已经存在的变异）； 2）“基因组结构”（控制特征的基因数量以及它们之间的物理和功能关系）。理论上，基因流，基因组结构和适应性之间的相互作用很复杂，在自然种群中基本上是意外的。在本应用中，我建议使用整个基因组测序和靶向基因测序的新型组合来测试基因流对局部适应和规范期间基因流对站立遗传变异和基因组结构的影响。我提出的程序有两个主题，使用海鸟作为模型系统：******主题我将测试站立变化在适应性和规范中的作用 - 育种时间的差异。在世界各地的几个群岛中，在形态上不同的是，在温暖与凉爽的季节中，风暴准群（Hydrobates spp。）在同一菌落中繁殖。我们将检验以下假设：与独立的突变或群岛之间的近期基因流有关，对不同群岛的季节性适应性产生。我们还将检验以下假设：基因组结构在发散过程中发生变化。******主题II测试了种间基因流对外周种群适应的贡献。具体而言，我们将测试1）从地面nesting Kittlitz的Murrrelets（Brachyramhus brevirostris）中的自适应渗入是否使树木纽约的大理石杂草（B. marmoratus）扩展到了范围内；和2）在更新世冰川期间祖先人群之间反复隔离和次要接触（基因流）的规格。它也是我们预测和希望减轻人为变化对生物多样性的影响的能力的组成部分。拟议的工作将为3博士学位，2个MSC和10名BSC学生提供基因组学，生物信息学和现场生态学的培训。***