基于倍性变化的全基因组遗传重组率的变异与分子机制研究

Polyploidy is one of the most common forms of the genomes in eukayotes, particularly flowering plants. Fast accumulating evidence supports a close structural and functional relationship between the genomes of the same species at different levels of polyploidy. As the most important driving force behind the evolution of genome structure and function, genetic recombination has long been a central topic in the evolutionary and developmental biology of chromosomes. It is the fundamental question whether the change in polyploidization of the genome is coupled with a genome-wide change in frequency of meiotic recombination. An answer to this question will open tremendous opportunities to tackle and explore a series of new and key questions in evolutionary biology such as the genome-wide distribution of recombination hot/cold spots, the mechanisms of neo-functionalization of duplicate genes, losses and gains in redundant genes etc. By proposing to combine the analytical powers of the modern sequencing techniques and advanced statistical methodology, this project is designed to tackle this fundamental question on a rigorous scientific basis. The project will create three segregation populations derived respectively from crossing diploid, allotetraploid and autotetraploid parental lines of Arabidopsis. The populations will be genotyped at 200~300 uniformly distributed genetic markers over the Arabidopsis genomes. The statistical methods, which properly account for the specific features and complexities of polysomic inheritance, will be developed to model and analyze the marker data in order to provide statistically appropriate estimates of the meiotic recombination frequencies from the Arabidopsis segregation populations at different polyploidy level. Conduct of this project will not only clarify the historically puzzling question about the polyploidy based change in meiotic recombination frequency at the genome-wide level but also may opens a new route for man controlled manipulation of meiotic genetic recombination in the plant kingdom.

多倍性是真核生物特别是开花植物物种进化中所经历的最重要的基因组形式。越来越多的实验数据表明，物种基因组的倍性变化伴随着其结构与功能的进化。作为基因组遗传变异与进化的重要动力，遗传重组一直是进化、发育生物学以及染色体功能研究的核心内容。基因组的倍性变化是否伴随细胞减数分裂遗传重组发生频率、热点/冷点分布的改变，进而加速基因组重复后，随即产生的重复基因新功能的进化、功能分化以及冗余基因的丢失是认识、揭示物种基因组倍性变化导致的基因组结构与功能进化机制的重要基础科学问题。本项研究将结合新一代测序实验技术和统计遗传学理论与方法学的研究，针对现有同类研究的严重缺陷，为在基因组水平回答物种倍性的变化是否伴随着基因组遗传重组的显著改变这一核心科学问题提供直接的实验科学证据以及严格的科学理论与分析方法。这项研究的实施不仅有助于澄清这一重要的科学问题，而且也为实现遗传重组人工调控的应用领域提供科学基础。

多倍性是真核生物特别是开花植物物种进化中所经历的最重要的基因组形式。越来越多的实验数据表明，物种基因组的倍性变化伴随着其结构与功能的进化。作为基因组遗传变异与进化的重要动力，遗传重组一直是进化、发育生物学以及染色体功能研究的核心内容。基因组的倍性变化是否伴随细胞减数分裂遗传重组发生频率、热点冷点分布的改变，进而加速基因组重复后，随即产生的重复基因新功能的进化、功能分化以及冗余基因的丢失是认识、揭示物种基因组倍性变化导致的基因组结构与功能进化机制的重要基础科学问题。本项研究结合新一代测序实验技术和统计遗传学理论与方法学的研究，针对现有同类研究的严重缺陷，为在基因组水平回答物种倍性的变化是否伴随着基因组遗传重组的显著改变这一核心科学问题提供直接的实验科学证据以及严格的科学理论与分析方法。