Genomic causes and consequences of sexually antagonistic selection

项目摘要/摘要 当一个等位基因对一种性别有利而对另一种性别有害时，性对抗选择(或称SA)就会起作用 其他的。它被认为对遗传疾病的维持、社会行为的变异以及 基因组结构的进化。尽管它对进化很重要，但我们对它的基因组影响知之甚少 因为经典的分子进化工具不能检测到它。这个项目将 从两个维度提升我们对SA的理解： 目标1将使用新方法通过测量等位基因频率之间的微小差异来检测SAS 雄性和雌性是由SA在当前一代中表现出来的。就个人而言，这些差异是 很少有统计意义上的差异，但我们最近发现，这些差异可以跨 基因组来检测和量化SA。我们将把这一策略应用于大样本的全基因组 有性二态程度不同的刺鱼的自然种群。结果将会是 提供对SAS全基因组强度的第一次估计，以及强加于 男性和女性，因为个体携带的等位基因适应了另一种性别。 Aim 2将提供第一个系统测试，以验证关于SAS驱动XY之间的转换这一普遍假设 和ZW性染色体系统。这些转变是基因组进化中的关键事件：它们重新连接了性别 决定途径，可以触发Y或W染色体的退化，并具有下游效应 关于人口统计学。虽然理论上表明这些转变可能是由SAS引起的，但没有系统的测试 这一假设已经得到了证实。这项研究将集中在诗状鱼类上，这些鱼类在 种间性别决定为XY和ZW。一种新的战略将被用来获得分阶段的 X、Y、Z和W染色体序列。这些染色体的基因树将在 他们进化了，测试了SAS假说的一个关键预测，并对非常年轻的人提出了前所未有的观点 W性染色体。 这项研究将产生两种主要的更广泛的影响。(I)它将开发一种新的检测方法 选择同时起作用，并决定其人口统计学影响。战略是一项重大的 与目前的方法背道而驰，目前的方法依赖于仅在许多世代中积累的基因签名。 新方法将应用于不同形式的选择和包括人类在内的其他物种。 (2)该项目将开发池鱼，作为所有四种性行为的第一个示范系统 可以研究染色体(X、Y、Z和W)。例如，将开辟重要的新研究领域 揭示了将性染色体限制在女性(W)是如何改变其进化的模式和节奏的。

Project Summary / Abstract Sexually antagonistic selection (or SAS) acts when an allele is beneficial to one sex but deleterious to the other. It is thought to be important to the maintenance of genetic diseases, variation in social behaviors, and evolution of genome structure. Despite its importance to evolution, we know little about the genomic impact of SAS in natural populations because the classical tools of molecular evolution cannot detect it. This project will advance our understanding of SAS in two dimensions: Aim 1 will use new methods to detect SAS by measuring the small differences between allele frequencies in males and females that result from SAS acting in the current generation. Individually, these differences are rarely statistically significant, but we recently discovered that these differences can be aggregated across the genome to detect and quantify SAS. We will apply this strategy to large samples of whole genomes from natural populations of stickleback fishes that differ in their degree of sexual dimorphism. The results will provide the first estimates of the genome-wide strength of SAS, and the total amount of mortality imposed on males and females because individuals carry alleles that are adapted to the other sex. Aim 2 will provide the first systematic test of the prevailing hypothesis that SAS drives transitions between XY and ZW sex chromosome systems. These transitions are key events in genome evolution: they rewire the sex determination pathway, can trigger the degeneration of the Y or W chromosome, and have downstream effects on population demography. While theory shows these transitions can result from SAS, no systematic test of the hypothesis has been carried out. The research will focus on poeciliid fishes that vary both within and between species for XY and ZW sex determination. A novel strategy will be used to obtain the phased sequences of X, Y, Z, and W chromosomes. Gene trees for these chromosomes will show the sequence in which they evolved, test a key prediction of the SAS hypothesis, and give unprecedented views of very young W sex chromosomes. The research will have two major kinds of broader impacts. (i) It will develop a new approach for detecting selection acting contemporaneously, and determining its demographic impact. The strategy is a major departure from current methods, which rely on genetic signatures that only accumulate over many generations. The new methods will have applications to diverse forms of selection and to other species, including humans. (ii) The project will develop poeciliid fishes as the first model system in which all four types of sex chromosomes (X, Y, Z, and W) can be studied. Important new research horizons will be opened, for example revealing how confining a sex chromosome to females (the W) alters the mode and tempo of its evolution.