Genomic causes and consequences of sexually antagonistic selection

项目总结/摘要 当一个等位基因对一种性别有利但对另一种性别有害时， 其他.它被认为是重要的维持遗传疾病，变异的社会行为， 基因组结构的进化尽管它对进化的重要性，我们对基因组的影响知之甚少。 SAS在自然种群中的存在，因为分子进化的经典工具无法检测到它。 从两个方面加深我们对SAS的理解： 目的1将使用新的方法来检测SAS，通过测量等位基因频率之间的微小差异， 男性和女性，导致SAS在当代的作用。个别而言，这些差异是 很少有统计学意义，但我们最近发现，这些差异可以在整个 基因组来检测和量化SAS。我们将把这一策略应用于大样本的全基因组， 在两性异形程度上不同的棘鱼的自然种群。结果将 提供了对SAS全基因组强度的第一次估计，以及对 因为个体携带适应另一性别的等位基因。 目标2将提供第一个系统测试的流行假设，即SAS驱动器之间的XY转换 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染色体的变性，并具有下游效应 关于人口统计学。虽然理论表明这些转变可以由SAS引起，但没有系统的测试表明， 假设已经实现。这项研究将集中在poecilid鱼类， XY和ZW性别决定的物种之间。一种新的策略将被用来获得阶段性的 X、Y、Z和W染色体的序列。这些染色体的基因树将显示序列， 他们进化，测试SAS假设的一个关键预测，并给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)它将开发一种新的方法来检测 选择同时发生，并决定其人口影响。该战略是一项重大战略 与目前的方法不同，目前的方法依赖于仅在许多代中积累的遗传签名。 新方法将应用于各种形式的选择和其他物种，包括人类。 (ii)该项目将开发Poecilid鱼类作为第一个模型系统，其中所有四种性别类型 染色体（X，Y，Z和W）可以进行研究。重要的新的研究领域将被打开，例如 揭示了限制女性性染色体（W）如何改变其进化的模式和克里思。

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.