4个肉牛品种微卫星多态性分析

本研究探讨了引进牛种（西门塔尔牛、利木赞牛）和山东地方黄牛（鲁西黄牛、利鲁牛）在20个微卫星位点上的多态性。试验从不同地区的种公牛站采集鲁西黄牛、利鲁牛、利木赞牛和西门塔尔牛的血液或精液样本，分别为56、27、31和30个，共计144个样本，血液样本采用Lab-Aid基因组DNA分离试剂盒提取基因组DNA，精液样本采用高盐法提取基因组DNA。利用20个微卫星标记，采用荧光标记毛细管电泳方法，对4个肉牛品种的DNA多态性进行分析，主要研究了每个群体的遗传变异指标（等位基因数、多态信息含量和杂合度）及群体间的遗传关系（F-统计量和基因流）。结果表明，肉牛基因组DNA条带整齐，无拖尾现象，质量较好，可用于本试验。20个微卫星座位中共检测到211个等位基因，平均等位基因数为10.6个。群体的平均观测杂合度在0.6147~0.7176之间，平均期望杂合度在0.6735~0.7862之间。在所有群体中各位点的多态信息含量在0.4853~0.8714之间，平均为0.7284，但在各个群体内的差异较大。近交系数及基因流分析结果表明，4个肉牛品种近交系数较低，群体间平均近交系数为0.085，每个微卫星位点的基因流均>1。总体来看，所选用的20个微卫星座位多态信息含量高，可作为有效遗传标记用于肉牛品种间遗传多样性分析。

Analysis of Microsatellite Polymorphism Among Four Beef Cattle Breeds

This study was conducted to evaluate the microsatellite polymorphism in the selected 20 microsatellite loci among four beef cattle including Simmental cattle, Limousin cattle, Luxi cattle and Lilu cattle. A total of 144 blood or semen samples from Simmental cattle, Limousin cattle, Luxi cattle and Lilu cattle were collected from different bull stations and the sample numbers were 56, 27, 31 and 30, respectively. The DNA from the blood or semen samples were extracted by Lab-Aid DNA separation kit or salt-extraction method, respectively. The DNA polymorphism of the four beef cattle was analyzed by fluorescence capillary electrophoresis method using the selected 20 microsatellite markers. The genetic variation indices (the number of alleles, polymorphism information content and heterozygosity) and genetic relationship (F-statistic and gene flow) among four beef cattle breeds were analyzed. The results showed that the DNA bands of the beef cattle was neat,and was suitable for the research. A total of 211 alleles were detected in the selected 20 microsatellite loci and the average number of allele in each locus was 10.6. The average observed heterozygosity (Ho) and average expected heterozygosity (He) among the beef cattle breeds were 0.6147 to 0.7176 and 0.6735 to 0.7862, respectively. The polymorphism information content (PIC) of four beef cattle breeds was 0.4853 to 0.8714 in the selected 20 microsatellite loci and the average value of PIC was 0.7284. The average inbreeding coefficient of the four beef cattle was 0.085 and the gene flow in each microsatellite locus was less than 1. In total, the selected 20 microsatellite loci had high polymorphic information, and were effective in the analysis of genetic diversity among different beef cattle breeds.