The prevalence of genetic introgression in speciation

摘要 背景：物种间遗传交换的重要性一直是争论的主题 在进化生物学家中。基因组数据表明，基因交换要普遍得多 甚至可能成为适应的来源。 广泛的、长期的目标：拟议的自然形成的混合区研究将利用自然的 在杂交区进行的一种实验，目的是找到混合的基因组，然后用它们来解剖 两个最近分化的果蝇物种之间不同的行为特征的遗传学。这样做的目的是 补充是为了促进Heidi Mavengere女士的专业发展。 具体目标：研究的目标1使用来自杂交区域的混合苍蝇来定位潜在的基因 温度偏好的生态重要特征。这一特征是生殖隔离的重要来源。 在果蝇物种中。混合图谱提供了一个独特的机会来识别基因和 最终导致生态位分化的过程。AIM 2将测试基因组预测 功能遗传学测试，以确认与表型差异相关的等位基因是否导致了 这一变化。 方法：果蝇属的果蝇可以在它们的自然栖息地收集并维护 在实验室条件下。在过去的几年里，我们改进了我们的测序方法，并 还开发了在多种果蝇物种中产生精确基因敲除的能力。这项建议 利用基因组中导入等位基因的鉴定来揭示种间遗传基础 不同之处。在这些混合分析中确定的基因将通过CRISPR- 介导的基因替换。我们对混合作图和基因组编辑的初步结果表明，我们 具有执行研究方案的能力。 与健康相关：在人类中混合标测是用于识别 致病基因变异。然而，后续实验要测试与之相关的基因的功能 疾病很难在人类身上表现出来。因此，混合映射协议从未得到验证 端到端，从识别与疾病相关的变异的种群水平，到功能 表现出表型状态的分子遗传水平。这项提案将研究涉及到的特征 利用混合作图进行生态生殖隔离，并将从统计上进行推断 基因组学到通过基因组编辑可测量的表型差异。 影响：这项研究的结果将提供第一个广泛的观点，在以下情况下的内向模式 物种在自然界中杂交，并将利用这些混合模式来剖析 导致生殖隔离的物种之间的行为差异。

ABSTRACT Background: The importance of genetic exchange between species has been a constant subject of debate among evolutionary biologists. Genomic data has demonstrated that gene exchange is much more common than previously thought and might even serve as a source of adaptation. Broad, long-term objective: The proposed study of naturally occurring hybrid zones will leverage the natural experiment that occurs in hybrid zones to find admixed genomes with which then can be used to dissect the genetics of behavioral traits that differ between two recently diverged Drosophila species. The goal of this supplement is to facilitate the professional development of Ms. Heidi Mavengere. Specific aims: Aim 1 of the study uses admixed flies from a hybrid zone to map genes underlying the ecologically important trait of temperature preference. This trait is an important source of reproductive isolation among Drosophila species. Admixture mapping provides a unique opportunity to identify the genes and processes that ultimately have led to divergence in ecological niche. Aim 2 will test genomic predictions using functional genetics tests to confirm whether the alleles associated with the phenotypic difference have caused the change. Method: Fruit flies from the genus Drosophila can be collected in their natural habitat and also maintained under laboratory conditions. In the last few years, we have improved our sequencing approaches and have also developed the ability to generate precise gene knock-outs in multiple species of Drosophila. This proposal leverages the identification of introgressed alleles in the genome to reveal the genetic basis of interspecific differences. The genes identified in these admixture analyses will be functionally validated with CRISPR- mediated gene replacements. Our preliminary results for admixture mapping and genome editing indicate we have the ability to execute the research proposal. Health-relatedness: Admixture mapping in humans is a primary approach used for the identification of disease-causing gene variants. However, follow-up experiments to test the function of genes correlated with disease are difficult to perform in humans. Admixture mapping protocols have therefore never been validated end-to-end from the population level at which variants correlated with disease are identified, to the functional molecular genetic level where the phenotypic state is manifested. This proposal will study traits involved in ecological reproductive isolation using admixture mapping and will connect inferences from statistical genomics to measurable phenotypic differences via genome editing. Impact: The results from this study will provide the first broad view of patterns of introgression in cases where species interbreed in nature, and will leverage those patterns of admixture to dissect the genetic basis of behavioral differences between species that cause reproductive isolation.