DISSERTATION RESEARCH: Evolutionary genetics of crossover rate differences across the Drosophila phylogeny

论文研究：果蝇系统发育中交叉率差异的进化遗传学

• 批准号: 1403154
• 负责人: Daven Presgraves
• 金额: $ 1.99万
• 依托单位: University of Rochester
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2014
• 资助国家: 美国
• 起止时间: 2014-06-01 至 2017-05-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1403154&HistoricalAwards=false
• 关键词: DISSERTATION; RESEARCH; Evolutionary; genetics; crossover

Meiosis is a specialized form of cell division that ultimately produces gametes (i.e., sperm and egg). This project will examine recombination, the exchange of genetic information between paired chromosomes, that occurs during meiosis. The project has broad educational and societal impacts, including opportunities to train undergraduate and high school students in classical genetics, basic molecular biology, and evolutionary biology. Furthermore, the portability of the experimental system facilitates outreach efforts involving middle school students participating in summer programs in science education. The research has potential societal impacts including human health as meiotic disruptions contribute to infertility and aberrant chromosome number in progeny. The recombination that occurs during the first stage of meiosis serves two important functions. First, recombination ensures the distribution of the appropriate number of chromosomes into gamete cells. Second, recombination generates novel genetic combinations that are potentially beneficial to the progeny. Despite these benefits, recombination has risks because it can generate deleterious duplication and deletion mutations. The frequency of recombination may therefore evolve to balance the benefits of recombination against its risks. Using the fly genus Drosophila, this research will investigate how the frequency and physical placement of recombination events along chromosomes has evolved between species. In particular, this research will investigate how the rapid molecular evolution of a meiosis gene has resulted in the evolution of differences in recombination rate observed across the evolutionary tree of Drosophila species. The project will investigate the rapidly evolving mei-218 gene which is responsible for most of the crossover rate difference between Drosophila melanogaster and Drosophila mauritiana using a candidate gene approach. The project will test the degree to which molecular evolution at mei-218 contributes to the variation in recombination rates across the Drosophila phylogeny using a molecular evolutionary analysis to test for histories of recurrent positive selection at mei-218 in multiple Drosophila lineages. The project will also use a transgenic approach to assay the phenotypic effects of the mei-218 gene from multiple Drosophila species.

减数分裂是细胞分裂的一种特殊形式，其最终产生配子（即，精子和卵子）。这个项目将研究重组，成对染色体之间的遗传信息交换，发生在减数分裂过程中。该项目具有广泛的教育和社会影响，包括在经典遗传学，基础分子生物学和进化生物学方面培训本科生和高中生的机会。此外，实验系统的便携性，促进了涉及中学生参加科学教育暑期课程的推广工作。这项研究具有潜在的社会影响，包括人类健康，因为减数分裂中断会导致后代不育和染色体数目异常。减数分裂第一阶段发生的重组有两个重要功能。首先，重组确保了适当数量的染色体分配到配子细胞中。第二，重组产生了对后代潜在有益的新的遗传组合。尽管有这些好处，重组也有风险，因为它会产生有害的重复和缺失突变。因此，重组的频率可能会演变，以平衡重组的好处和风险。利用果蝇属，这项研究将调查的频率和物理位置的重组事件沿着染色体已演变的物种之间。特别是，这项研究将调查如何减数分裂基因的快速分子进化导致了在果蝇物种的进化树中观察到的重组率差异的演变。该项目将使用候选基因方法研究快速进化的mei-218基因，该基因是黑腹果蝇和毛里求斯果蝇之间交换率差异的主要原因。该项目将使用分子进化分析来测试mei-218的分子进化在多大程度上有助于果蝇遗传学中重组率的变化，以测试mei-218在多个果蝇谱系中的周期性正选择历史。该项目还将使用转基因方法来分析来自多个果蝇物种的mei-218基因的表型效应。