The genetics and population genomics of divergence between Xiphophorus malinche and Xiphophorus birchmanni and their effects on patterns of introgression.

项目概要/摘要： 最近才分化的物种有时会在自然界和遗传学上重新接触- 吃混血儿这可能导致基因渗入，即遗传物质从一个物种进入另一个物种。 另基因组数据的最新研究表明，基因渗入既广泛又重要， 遗传变异的主要来源。例如，人类基因组的一部分可以追溯到他们的祖先， 尼安德特人或丹尼索瓦人，有证据表明这种基因渗入是适应性的。 研究基因渗入的模式可以获得有关种群历史、选择和进化的信息。 保持物种独特性的基因这项研究的目的之一是开发和应用- 有助于解释自然种群中基因渗入模式的理论模型。 这将有助于理解物种之间的基因流动如何受到选择的影响。 本研究将在剑尾鱼Malinche/X. birchmanii物种对， 野生环境中大量的杂交种群。将分析这些人群的基因组数据以了解 更多关于这两个物种之间的基因渗入过程。 本研究的第二个目的是了解生物学的分歧和生殖异源， lation.这将集中在绘制性状，如色素沉着，是不同的X。马林切 和X.伯奇曼尼。利用野生杂交个体和实验室F2的基因组数据 杂交后代，这些特征将被映射到基因上。这将有助于理解特质如何 例如色素沉着和剑的生长是发育调节的， 物种形成过程中的进化分化过程。本研究的两个目标将 整合，并一起将确定编码对维持不同的重要性状的基因。 物种，并明确描述如何选择在自然界中对他们的作用。

Project Summary/Abstract: Species that are very recently diverged sometimes come back into contact in nature and gener- ate hybrids. This can result in introgression, the movement of genetic material from one species into another. Recent studies of genomic data indicate that introgression is both widespread and an impor- tant source of genetic variation. For example, portions of the human genome trace their ancestry back to Neanderthals or Denisovans, and evidence suggests that some of this introgression was adaptive. Studying patterns of introgression can yield information about population history, selection, and the genes involved in keeping species distinct. One objective of this research is to develop and apply the- oretical models that will aid in the interpretation of patterns of introgression in natural populations. This will contribute to an understanding of how gene flow between species is influenced by selection. This research will be carried out in the Xiphophorus malinche/X. birchmanii species pair, which form large hybrid populations in the wild. Genomic data from these populations will be analyzed to learn more about the process of introgression between the two species. A second objective of this research is to understand the biology of divergence and reproductive iso- lation. This will focus on mapping traits, such as pigmentation, that are different between X. malinche and X. birchmanni. Using genomic data from both wild-caught hybrid individuals and laboratory F2 hybrids, these traits will be mapped to genes. This will contribute to an understanding of how traits such as pigmentation and sword growth are developmentally regulated, as well as an understanding of the process of evolutionary divergence during speciation. The two objectives of this research will be integrated, and together will identify genes that encode traits important for maintaining distinct species, and explicitly describe how selection acts on them in nature.