Comparative genomic analysis of hybridization and speciation: uncovering genes and traits responsible for diversification

杂交和物种形成的比较基因组分析：揭示负责多样化的基因和性状

• 批准号: 311931-2012
• 负责人: Irwin, Darren
• 金额: $ 2.99万
• 依托单位: University of British Columbia
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2016
• 资助国家: 加拿大
• 起止时间: 2016-01-01 至 2017-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=595033
• 关键词: Comparative; genomic; analysis; hybridization; speciation

There is abundant evidence for the process of speciation, whereby a single species evolves into two, but the selective forces that drive this process are under much debate. Hybrid zones, regions where different but related species come into contact and interbreed to some extent, provide excellent opportunities to determine which traits are most involved in speciation. Western Canada has many hybrid zones between distinct western and eastern forms of birds that evolved differences while they were separated in different southern regions during the Ice Ages. Across a number of different hybrid zones, we will study variation in a variety of traits, determining which traits show the sharpest change across each zone; these are likely the traits most involved in speciation. We will also use a recently developed method of genetic analysis called next-generation DNA sequencing to identify genes associated with traits of interest. To understand the location of these genes in the genome (e.g., on what chromosome), we will use next-generation sequencing to assemble the genome of one reference individual for each hybrid zone. One important trait is seasonal migration. Many pairs of western and eastern species differ dramatically in the routes that they take from their breeding ranges to their wintering ranges. We hypothesize that hybrids have intermediate migratory orientations and suffer lower survival as a result. We will determine orientation behavior of birds in each hybrid zone using tracking devices and orientation cages, and will determine the genetic regions associated with differences in migration. Our work will also (1) use genomic analysis to reconstruct the history of several species that may have arisen through hybridization of other species, and (2) test whether there are certain key genomic regions, such as the sex chromosomes, that play a strong role in speciation within birds. By generating assembled genomes and gene-trait association studies in six groups of hybridizing species, we will contribute much knowledge toward future studies of the genetic basis of adaptation and speciation.

有大量的证据表明物种形成的过程，即一个物种进化成两个物种，但驱动这一过程的选择力仍有很多争议。杂交区，不同但相关的物种在某种程度上接触和杂交的区域，提供了很好的机会来确定哪些特征最参与物种形成。加拿大西部有许多不同的西部和东部鸟类之间的杂交区，这些鸟类在冰河时代被分离在不同的南部地区时进化出了差异。在许多不同的杂交区，我们将研究各种性状的变异，确定哪些性状在每个区域中变化最大;这些性状可能是物种形成中最重要的性状。我们还将使用最近开发的称为下一代DNA测序的遗传分析方法来识别与感兴趣的性状相关的基因。为了了解这些基因在基因组中的位置（例如，在什么染色体上），我们将使用下一代测序来组装每个杂交区的一个参考个体的基因组。一个重要特征是季节性迁移。许多对西部和东部的物种在从繁殖区到越冬区的路线上有很大的不同。我们假设杂交种具有中间迁移方向，因此存活率较低。我们将使用跟踪装置和定向笼确定每个杂交区中鸟类的定向行为，并确定与迁移差异相关的遗传区域。我们的工作还将（1）使用基因组分析来重建可能通过其他物种杂交而产生的几个物种的历史，以及（2）测试是否存在某些关键的基因组区域，如性染色体，在鸟类的物种形成中发挥重要作用。通过在六组杂交物种中产生组装的基因组和基因-性状关联研究，我们将为适应和物种形成的遗传基础的未来研究贡献更多的知识。