Identifying Genetic Determinants of Speciation from Genomic Maps of Ancestry in Hybrid Mice

为什么有这么多种类？从一个物种产生两个物种的过程（物种形成）是生物多样性的主要决定因素。当物种在自然界中杂交时，其基因组的某些部分会发生交换，而其他部分则不会。基因组中那些未交换的区域使物种保持分离。通过识别小鼠物种中的那些不相容区域，这项研究将揭示负责物种形成（和生物多样性）的遗传机制。这项研究的另一个新贡献是开发分析整个基因组而不是一次分析一个区域的新方法。该项目将把研究与教师培训结合起来，与公众分享发现。除了扩展进化知识之外，这项研究还将有益于包括人类健康在内的应用领域。例如，该项目开发的框架可用于了解人类和尼安德特人之间历史交配的当前生殖影响。这项研究将为测量杂交区物种之间的基因流提供新的理论和经验框架。重点将是祖先连接点——沿着染色体的那些点，祖先从一个物种切换到另一个物种。与现有的混合基因组分析相比，这种方法可以轻松扩展到整个基因组。计算机模拟将用于量化选择、迁移和遗传漂变对整个基因组祖先连接的影响。将研究一系列生殖隔离的遗传结构，以确定对杂种的选择留下可检测的基因组特征的条件。该理论框架将应用于在两个家鼠亚种之间的杂交中收集的新基因组数据，这两个亚种是研究正在进行中的物种形成的优秀模型。将确定造成新物种之间生殖障碍的不相容基因组区域。

Why are there so many species? The process by which two species are generated from one - speciation - is a major determinant of biodiversity. When species hybridize in nature, some parts of their genomes are exchanged and others are not. Those regions of the genome that are not exchanged keep the species separate. By identifying those incompatible regions in species of mice, this research will reveal genetic mechanisms responsible for speciation (and biodiversity). Another novel contribution of this research will be the development of new approaches that analyze entire genomes, instead of one region at a time. The project will combine research with teacher training to share discoveries with the public. In addition to expanding evolutionary knowledge, this research will benefit applied fields, including human health. For example, the framework developed in this project can be used to understand the current reproductive effects of historical mating between humans and Neanderthals.This research will provide new theoretical and empirical frameworks for measuring gene flow between species in hybrid zones. The focus will be ancestry junctions - those points along chromosomes where ancestry switches from one species to the other. In contrast to existing analyses of hybrid genomes, this approach will easily scale to entire genomes. Computer simulations will be used to quantify the effects of selection, migration and genetic drift on ancestry junctions across the genome. A range of genetic architectures of reproductive isolation will be investigated to determine the conditions under which selection against hybrids leaves detectable genomic signatures. This theoretical framework will be applied to new genomic data collected in hybrids between two subspecies of house mice that are excellent models for studying speciation in progress. Incompatible genomic regions responsible for reproductive barriers between new species will be identified.