DISSERTATION RESEARCH: Chromosome inversions and reproductive isolation in an avian hybrid zone

论文研究：鸟类杂交区的染色体倒位和生殖隔离

• 批准号: 1601323
• 负责人: Trevor Price
• 金额: $ 1.97万
• 依托单位: University of Chicago
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2016
• 资助国家: 美国
• 起止时间: 2016-06-01 至 2017-05-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1601323&HistoricalAwards=false
• 关键词: DISSERTATION; RESEARCH; Chromosome; inversions; reproductive

Scientists' understanding of the way in which two species arise from a common ancestor has greatly improved since the time of Darwin. We now know that the most common way species form is when different populations become geographically separated from each other and begin to genetically diverge. We also know that this process can take millions of years. But at any time, during the process of splitting, populations may come back into contact and form a narrow zone of contact where individuals from one group mate with individuals from the other group (a hybrid zone). While hybridization generally leads to a slowdown in the rate at which new species form because their genomes are no longer separate, several mechanisms have been identified whereby hybridization can actually promote divergence. This project focuses on the evolution of chromosome inversions, rearrangements to the structure of the genome that act as genetic barriers between young species that share some gene exchange in narrow hybrid zones. This information is critical to understanding the natural consequences of geographic divergence, periodic gene exchange, speciation, and the resulting biodiversity that is present on Earth. Education-related public outreach efforts at the Field Museum of Natural History, where the research takes place, will involve Chicago area high school and undergraduate students.These researchers study a hybrid zone between subspecies of the long-tailed finch (Poephila acuticauda). Subspecies differ in beak color (yellow vs. red) and hybridize across a narrow contact zone in northern Australia. Genetic differences between subspecies are largely restricted to one chromosome. Several large chromosome inversions are on the same chromosome. The researchers will examine the genomes of individual birds from across the hybrid zone to identify the genes encoding a reproductive isolating trait: beak color.

自达尔文时代以来，科学家们对两个物种起源于一个共同祖先的理解已经有了很大的提高。我们现在知道，物种形成的最常见方式是不同的种群在地理上彼此分离，并开始发生遗传分化。我们也知道这个过程可能需要数百万年。但在分裂过程中的任何时候，种群都可能重新接触，形成一个狭窄的接触区，其中一个群体的个体与另一个群体的个体交配（杂交区）。虽然杂交通常会导致新物种形成的速度放缓，因为它们的基因组不再是分开的，但已经确定了几种杂交实际上可以促进分歧的机制。该项目的重点是染色体倒位的进化，基因组结构的重排，作为年轻物种之间的遗传屏障，在狭窄的杂交区共享一些基因交换。这些信息对于理解地理差异、周期性基因交换、物种形成以及由此产生的地球上的生物多样性的自然后果至关重要。这项研究在菲尔德自然历史博物馆进行，与教育相关的公共宣传工作将涉及芝加哥地区的高中生和本科生。这些研究人员研究长尾雀（Poephila acuticauda）亚种之间的杂交区。亚种的喙颜色不同（黄色与红色），在澳大利亚北方的一个狭窄的接触区杂交。亚种之间的遗传差异主要局限于一条染色体。几个大的染色体倒位在同一条染色体上。研究人员将检查来自杂交区的单个鸟类的基因组，以确定编码生殖隔离特征的基因：喙的颜色。