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

项目摘要/摘要： 最近分化的物种有时会重新接触大自然和基因- 吃了混血儿。这可能导致渗入，即遗传物质从一个物种转移到 又一个。最近对基因组数据的研究表明，导入既是普遍的，也是一种障碍。 遗传变异的另一个来源。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，这种内向是适应的。 研究渐渗模式可以获得有关种群历史、选择和 与保持物种不同有关的基因。这项研究的目标之一是开发和应用- 理论模型，这将有助于解释自然种群中的渐渗模式。 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。 这项研究将在剑尾鱼/白纹伊蚊物种对中进行，这对物种对形成了 野生的大量杂交种群。来自这些种群的基因组数据将被分析以了解 更多关于这两个物种之间相互渗透的过程。 这项研究的第二个目标是了解发散和生殖等同的生物学。 发音。这将侧重于定位不同于马林氏X.Malinche的性状，如色素沉着 和X.Birchmanni。使用来自野生捕获的杂交个体和实验室F2的基因组数据 杂交种，这些特征将被定位到基因上。这将有助于理解特征是如何 如色素沉着和剑的生长是发育调节的，以及理解 物种形成过程中进化分化的过程。这项研究的两个目标将 被整合在一起，将共同识别编码对保持独特的重要特征的基因 物种，并明确描述自然界中选择如何作用于它们。

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.