【作者】 徐华；

【导师】 孙少华；

【作者基本信息】 河北农业大学 ， 动物遗传育种与繁殖， 2004， 硕士

【摘要】 选育优质高产的奶牛是提高其生产性能和牛场经济效益的主要途径，传统的通过外貌鉴定和生产性能测定由于存在环境因素的影响和时间、性别上的限制，局限性较大，而通过分子遗传标记结合生产性状进行奶牛遗传品质的选择是克服上述方法缺陷而且准确性强的选育方法。 本实验选取了石家庄三鹿直属奶牛场和容城宏利达奶牛场共计130头荷斯坦奶牛，提取了其血液DNA，应用PCR-RFLP和微卫星DNA多态性检测技术，分别对荷斯坦奶牛的催乳素基因(PRL)和四个微卫星座位进行了DNA多态性分析，采用最小二乘模型分析催乳素(PRL)基因和微卫星座位的DNA多态性与奶牛产奶性能之间的关系。 对中国荷斯坦奶牛催乳素(PRL)基因进行PCR-RFLP分析，检测到两个等位基因(A、a)、三种基因型(AA、Aa、aa)，结果如下：对于基因频率，等位基因A为0.7538，等位基因a为0.2462。对于基因型频率，AA型为0.5462，Aa型为0.4154，aa型为0.0385。_χ2适合性检验的结果表明，催乳素基因在荷斯坦奶牛群体中处于Hardy-Weinberg平衡状态。催乳素基因的杂合度为0.3711，有效等位基因数为1.5901，多念信息含量为0.3022，属于中度多态。 本实验还利用四个微卫星座位(ILSTS103、ILSTS96、CSSM66和BM6425)分析了荷斯坦奶牛群体的遗传结构和遗传变异，对四个微卫星座位的基因频率和基因型频率表进行了_χ2检验，结果表明这四个微卫星座位在荷斯坦奶牛群体中均处于Hardy-Weinberg平衡状态。经过_χ2独立性检验，同位于牛第14号染色体上的CSSM66和BM6425座位之间不存在连锁关系，二者在遗传上是相互独立的。根据等位基因频率计算得到的座位的等位基因数、平均多态信息含量、有效等位基因数和杂合度在群体中表现的范围分别为5～11、0.78～0.88、4.83～8.19和0.79～0.88，说明这四个微卫星座位在荷斯坦奶牛群体中表现出较高的多态性，同时也说明了在我国荷斯坦奶牛群体内具有较大的选择潜力。 催乳素基因和四个微卫星座位对产奶量和乳成分影响的最小二乘统计分析结果表明，场、年、胎次等系统环境因素对奶牛产奶量影响极显著(p＜0.01)，另外，场对乳糖率的影响也达到极显著水平(p＜0.01)；催乳素基因对产奶量的影响均达到显著水平(P＜0.05)；ILSTS103、CSSM66、BM6425三个微卫星座位对产奶量的影响均达到极显著水平(P＜0.01)；ILSTS103、CSSM66和BM6425对乳蛋白率的影响显著(P＜0.05)，CSSM66还对乳脂率和干物质率的影响分别达到了极显著(p＜0.01)和显著水平(P＜0.05)；没有检测到ILSTS96对产奶性能显著影响。更多还原

【Abstract】 Selection of high quality catties is primary approach for increasing catties production performance and dairy farms economic benefit. Traditional judging of exterior and production performance have bigger limitation because of environmental factor influence and time, sex confinement, but selection of molecule genetic marker combining production trait for dairy genetic quality is high accuracy method to conquer these limitations.This experiment selects 130 Holstein dairy catties in the dairy farm belonging to Shi Jiazhuang Sanlu Group and the Honglida dairy farm in Rongcheng totally.Applied PCR-RFLP and microsatellite DNA polymorphism detection technique, Prolactin (bPRL) and four microsatellite loci Holstein cattle are analysed for DNA polymorphism. Effects of bPRL and microsatellite loci on milk performance were examined using least squares model.Frequency of variants in PRL were: PRL(A)0.7538, PRL(a)0.2462. For the genotype frequency of PRL, the genotype of AA is 0.5462, Aa is 0.4154, aa is 0.0385. The gene frequency and genotype frequency of PRL were analysed using chi-square test. The result showed that the Holstein dairy cattle lies in Hardy-Weinberg equilibrium state. The heterozygsity, number of effective alleles, and polymorphism information content were 0.3711, 1.5901, 0.3022, respectively. The PIC showed the medium polymorphism.This experiment made use of four microsatellite loci (ILSTS103, ILSTS96, CSSM66, BM6425 )analyzing dairy cattle construction and variation with inherit. The gene frequency and genotype frequency of four microsatellite loci were analysed using chi-square test. The result showed that the Holstein dairy cattle lies in Hardy-Weinberg equilibrium state. Through Chi-square independence test, the CSSM66 and BM6425 locating on the No. 14th chromosome together, is mutually independent on the heredity. The gene frequency and genotype frequency of four microsateliite loci were analysed using chi-square test. The result showed that the Holstein dairy cattle lies in Hardy-Weinberg state. The number of alleles, range of the polymorphism information content, number of effective alleles and the heterozygsity in the population .were 5 - 11, 0.78-0.88, 4.83~ 8.19 and 0.79~0.88. These resulted show that four microsatellite loci in Holstein cattlehave high polymorphism. So there was a large selection potential in dairy cattle population. Least squares analysis showed that herd, year, season of calving and parity had significant effects on milk yield(P<0.01), In addition,herd had significant effects on lactose percent. PRL and three microsatellite loci(ILSTS103, CSSM66, BM6425) had significant effect on milk yield (P<0.05 or P<0.01). In addition, ILSTS103, CSSM66 and BM6425 had significant effects on protein percent (P<0.05), and CSSM66 had significant effects on fat percent and drymatter percent (P<0.05) .ILSTS96 hadn’t significant effect on milk prodution.更多还原