【作者】 李俊营；

【导师】 陈宏；

【作者基本信息】 西北农林科技大学 ， 动物遗传育种与繁殖， 2007， 硕士

【摘要】 采用微卫星DNA标记技术和PCR-RFLP技术对5个山羊品种(崂山奶山羊、西农萨能奶山羊、关中奶山羊、板角山羊和贵州白山羊) 11个微卫星位点、DQA1和DQA2基因的遗传多样性进行了分析,探讨了各品种内的遗传变异及群体间的遗传关系,并分析了多态性基因座和多态性微卫星位点与崂山奶山羊和西农萨能奶山羊体尺指标、产奶性能以及产羔数的关系,旨在为山羊遗传资源的合理开发、利用及保护提供科学依据。1.应用筛选出的11个微卫星DNA标记对5个山羊品种进行了多态性分析。(1)除了BM203和BM6425外,其余的9个位点均具有多态性,共检测到了85个等位基因,平均每个位点检测到9.4个等位基因。表明这9个微卫星位点在5个山羊群体中多态性比较丰富。(2)以等位基因为基础,得出所有位点的平均杂合度在0.6649~0.8379之间,群体平均杂合度在0.7313~0.8002之间。9个微卫星位点均为高度多态(PIC>0.5),说明这5个山羊品种遗传变异大,遗传多样性丰富,遗传基础比较广泛。(3)对9个微卫星位点进行了中性测试,发现3个微卫星位点(BM315、BM1329和TGLA68)在95%的置信区间内,属于中性位点,而其余的6个位点则为非中性位点。(4)计算了总群杂合度和亚群杂合度以及遗传分化系数,表明群体间遗传变异程度不高;对所有微卫星位点进行F-统计量分析,Fst的变化范围是从BM1329的0.0304到BM315的0.1401,群体每代的迁移数在1.5351~7.9765,平均为4.2998。(5)计算了五个山羊群体的Nei氏标准遗传距离,并进行了UPGMA聚类分析,结果与这些山羊品种的起源、育成史和地理分布相符合。2.分析了微卫星不同基因型与崂山奶山羊和西农萨能奶山羊的生长发育性状和产奶量以及产羔数等指标之间的相关性,结果如下:(1)对生长发育性状的效应进行了分析,发现品种为其主要效应,也找到了一些性状的标记效应,并计算了其基因型的最小二乘均值。(2)对产奶量和产羔数的效应进行了分析,没有找到标记效应,品种效应为主要效应。3.应用PCR-PFLP方法对5个山羊品种的DQA1和DQA2基因座进行了多态性分析。在DQA1基因的两个酶切位点上,除了西农萨能奶山羊为中度多态外,其它4个品种均为低度多态。在DQA1-TaqⅠ-RFLP位点上,关中奶山羊和崂山奶山羊处于Hardy-Weinberg不平衡状态,而西农萨能奶山羊、板角山羊和贵州白山羊上均处于Hardy-Weinberg平衡状态;在DQA1-HaeⅢ-RFLP位点上,5个山羊群体中均处于Hardy-Weinberg平衡状态。在DQA2-PvuⅡ-RFLP位点上为单态。在DQA2-HaeⅢ-RFLP位点上,5个山羊群体在该位点上均处于Hardy-Weinberg不平衡状态(P>0.05)。除了西农萨能奶山羊属于高度多态外,其它4个山羊品种均处于中度多态。4.对DQA1和DQA2多态基因座与崂山奶山羊和西农萨能奶山羊的生长发育性状和产奶量以及产羔数等指标进行了关联分析,结果发现多态基因座对所有指标影响差异均不显著(P>0.05)。更多还原

【Abstract】 In this paper, microsatellite DNA markers and PCR-RFLP technology were employed to detect the molecular genetic diversity of eleven microsatellite loci, DQA1 and DQA2 genes in five goat breeds, e.g. Laoshan dairy goat, Xinong Sannen dairy goat, Guanzhong dairy goat, Banjiao goat and Guizhou white goat. The genetic variability within populations and genetic relationships among them were discussed. Relationships between different genotype and body sizes, milk yields and litter sizes were analysed based on polymorphism. The study was aimed to provide scientific basis for proper development and protection of these goat breeds. The results were as followed:1. Eleven microsatellite loci were used to evaluate the genetic polymorphisms in five goat breeds.(1) Apart from BM203 and BM6425, the other nine loci were polymorphic and eighty-five alleles were detected, with a mean of 9.4, which indicted that the nine loci were more polymorphic in the five goat breeds.(2) Based on alleles, the average heterozygosity of overall loci and populations ranged from 0.6649 to 0.8379, 0.7313 to 0.8002, respectively. The nine loci were high polymorphic (PIC>0.5). This showed that there were great variability and broad genetic base in the five goat breeds.(3) Neutrality test was conducted on the nine loci in the five goat populations. Three microsatellite loci (BM315、BM1329 and TGLA68) was in confidence interval (95%) and on the contrary the other six loci were not neutral loci.(4) Heterozygosity in subpopulation, Total Heterozygosity, and coefficient of gene differentiation (Gst) of the nine microsatellite loci were calculated, which demonstrated small genetic differentiation between the five goat breeds. F-statistics of each microsatellite locus was analysed and the value of Fst and Nm ranged from 0.0304 (BM1329) to 0.1401 (BM315), 1.5351 to 7.9765 (the mean was 4.2998), respectively. (5) Genetic distance was calculated among the five goat breeds and UPGMA tree was constructed, which showed that the results were in accordance to their origin, history and geographical distribution.2. Relationships between microsatellite markers and two dairy goat breeds’production traits were analysed. The results were as followed:(1) The analysis result of growth trait showed the effects of breed were major effect. Some marker effects were found and the least square means were obtained.(2) The analysis result of milk yield and litter sizes showed the effects of breed were major effect in most indexs. No marker effects were found in the two dairy breeds.3. The genetic polymorphisms of DQA1 and DQA2 were detected by PCR-RFLP in five goat breeds. At the two RFLP loci of DQA1 gene, SN was moderate polymorphisms and the other four populations were low polymorphisms. Except GZ and LS, other three populations (SN, BJ and GW) were at Hardy-Weinberg equilibrium at TaqⅠ-RFLP locus. At the HaeⅢ-RFLP locus, the five populations were at Hardy-Weinberg equilibrium.There was no polymorphism at the DQA2 PvuⅡ-RFLP locus. At the DQA2 HaeⅢ-RFLP locus, the five goat populations were not at Hardy-Weinberg equilibrium. Apart from SN with high polymorphisms, the other four populations showed moderate polymorphisms.4. The effects of genotypes of the two genes on the traits were analysed by linear model and there were not statistically significantly between the effects of genotypes and the traits.更多还原