Exploring the Role of Altered Hybrid Recombination in Contributing to Speciation

描述（由申请人提供）：进化生物学中的一个主要问题，确定生物多样性的遗传来源，最好通过检查物种形成界面的物种来回答-已知杂交的密切相关物种。最近的遗传学进展突出了这些物种中杂交的普遍性。此外，密集标记分析表明，物种之间的遗传交换并不是均匀分布在整个基因组中。该提案旨在了解哪些因素导致了遗传景观中基因流动的区域差异。 物种形成的许多工作都集中在理解那些产生繁殖障碍的因素上，特别是集中在物种之间差异很大的地区。这些区域可能对应于在不同遗传背景下选择的物种形成基因，或限制物种间基因交换的结构变体，如染色体倒位。除了倒位，没有结构特征已被确定，通常区分最近分歧的物种。 我们的研究建议调查许多杂交类群，并了解是什么导致了物种间遗传交换的变化。具体来说，我们建议计算预测重组率的差异，在杂交种内的连锁图谱。然后，我们将确定杂交重组率的变化（与种内重组率相比）是否与种间核苷酸差异的变化相关。我们预测，这种相关性将突出显示在物种形成中重要的基因组区域。这些变化可能是由于遗传变异的作用，就像倒位，以防止杂交等位基因被纳入基因组。因此，我们计划在我们的分类群调查中解剖这些区域，并检查这些区域是否具有任何共同的遗传元素，这些遗传元素可以区分最近分化的物种，从而有助于形成这种模式。 最近对人类的研究揭示了个体内和个体间基因组结构变异的广泛证据。其中一些变异与疾病有关;然而，我们对这些变异在促进我们基因组结构方面的作用的总体理解仍然有限。我们的研究旨在了解这些变异是否通过破坏基因交换而在促进物种形成中发挥作用，这也与疾病有关。通过利用各种生物系统中的现有数据，我们的研究结果有可能预测基因组的哪些区域可能对其他研究系统中的物种形成很重要。

DESCRIPTION (provided by applicant): A major question in evolutionary biology, determining the genetic source of biodiversity, is best answered by examining species at the interface of speciation - closely related species that are known to hybridize. Recent genetic advances have highlighted the pervasiveness of hybridization in these species. Further, dense marker analysis shows that genetic exchange between species is not uniformly distributed across the genome. This proposal aims to understand which factors contribute to this regional variation in gene flow across the genetic landscape. Much work in speciation has been focused on understanding those factors that produce barriers to reproduction, focusing particularly on regions where divergence between species is high. These regions may correspond to speciation genes that are selected against in different genetic backgrounds, or structural variants such as chromosomal inversions that limit interspecies gene exchange. Beyond inversions, no structural features have been identified which commonly differentiate recently diverged species. Our research proposes to survey many hybridizing taxa and understand what contributes to variation in genetic exchange between species. Specifically, we propose to computationally predict recombination rate differences in hybrids relative to within species linkage maps. We will then determine if changes in hybrid recombination rates (as compared to within-species recombination rates) are associated with changes in between species nucleotide divergence. We predict that this correlation will highlight regions of the genome important in speciation. These changes could be due to genetic variants that act like inversions to prevent hybrid alleles from being incorporated into the genome. Therefore, we plan to dissect these regions in our survey of taxa and examine if these feature any common genetic elements that distinguish recently diverged species could contribute to the pattern. Recent research in humans has revealed extensive evidence of genomic structural variation within and between individuals. Some of these variants have been connected to disease; however, our overall understanding of the role of these variants in contributing to the structure of our genome is still limited. Our stuy aims to understand if these variants play a role in facilitating speciation by disrupting genetic exchange, which has also been linked to disease. By making use of existing data in a variety of biological systems, the results of our research have the potential to make predictions about which regions of the genome are likely to be important in speciation in other research systems.