偏分离群体连锁图构建中高通量分子标记顺序的研究

Genetic linkage maps have become an indispensable tool for locating genes or quantitative trait loci, marker assisted breeding and map-based gene cloning. A basic assumption in reconstruction of genetic linkage maps is that markers follow the Mendelian segregation ratio. The non-Mendelian segregation of markers, which deviates from the Mendelian ratio affects not only the estimation of genetic distance between two markers but also the order of markers on a same linkage group. We considered effects of segregation distortion on the ordering of markers and finding suitable approximate algorithms for mapping high-density genetic markers showing segregation distortion. A primary difficulty in ordering genetic loci using linkage analysis is the large number of possible orders. The ordering of markers within linkage groups is considered a special case of the classical Traveling Salesman Problem. Recently, several algorithms to obtain approximate solution for ordering markers have been proposed. Toward different mapping populations and different criterions, we want to classifying these algorithms and finding the suitable algorithms with respect to different situations. Monte Carlo simulations were conducted to evaluate the mapping efficiency taking several factors into consideration. Our final target is to develop an application software based on windows interface.In addtion, we would like to have more than two SCI articles publicated.

连锁遗传图对数量性状基因座定位、基因组拼接、标记辅助育种和基因图位克隆有重要作用。遗传连锁图构建是以分子标记服从Mendel分离比例为基础的，但是双亲分离群体中有较多标记并不符合这一假定，可能导致连锁图中标记顺序和标记间遗传距离估计的错误。在前期偏分离群体连锁图标记间遗传距离矫正和最优化算法工作基础上，本课题探索偏分离对连锁图高通量分子标记顺序的影响。由于连锁图标记排序的所有可能数目非常巨大，将这个排序问题视为旅行售货员问题（TSP）的一个特例，可能是解决该问题的有效方法。为此，将已有的解决TSP问题的多种近似算法和分子标记排序算法结合起来，在不同群体和评价标准情况下，研究这些整合算法的优劣，找到最优的整合算法，并用Monte Carlo模拟比较这些算法正确性和精确度，希望找到解决连锁图构建中高通量偏分离标记排序问题的最优算法，研制Windows界面的软件包。发表SCI论文2篇。

连锁遗传图对数量性状基因座定位、基因组拼接、标记辅助育种和基因图位克隆有重要作用。在前期偏分离群体连锁图标记间遗传距离矫正和最优化算法工作基础上，本课题探索偏分离对连锁图高通量分子标记顺序的影响。由于连锁图标记排序的所有可能数目非常巨大，将这个排序问题视为旅行售货员问题（TSP）的一个特例，可能是解决该问题的有效方法。在我们的研究中，通过LSZZH(P1)和NN493-1(P2)正反交得到的518个RIL和它们的亲本的基因型都确定了并测定了大豆种子的亚油酸在三种环境中的含量。所有的SNP标记，包括很显著的偏分离标记用来构建高通量的连锁图。另外我们还研究了这些偏分离标记对连锁图的构建和QTL定位的影响。为了验证构建的连锁图的精度，我们还检测了确定大豆亚油酸含量的数量基因座。关于大豆的11846个标记在20条染色体的上的分布情况以及相应的连锁图也有相应结果。