【作者】 李瑞彪；

【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， 2003， 硕士

【摘要】 西农萨能奶山羊是上世纪20～30年代从美国和英国引进，在西北农业大学经多年选育而成的一个优良培育品种。该羊具有体格高大、适应性强、遗传性能稳定、产奶量高等特点，是关中奶山羊和崂山奶山羊等育成品种的父系品种之一。本研究用RAPD技术对西农萨能奶山羊初生重、体尺发育进行了标记研究，用RAPD、PCR-RFLP、PCR-SSCP、微卫星标记共四种方法对西农萨能奶山羊产奶量性状进行了标记研究，旨在揭示西农萨能奶山羊的遗传种质特性，找到影响西农萨能奶山羊产奶量、初生重、体尺发育等的分子标记，为其进一步选育提高提供科学依据。 本研究得到以下几个方面的结论： 1．西农萨能奶山羊的RAPD遗传特性 本实验从64条随机引物中筛选出6条引物，对56只奶山羊进行RAPD扩增，共得到58条带，其中34条具有多态性，多态带频率为58.6％，说明多态性丰富。经分析，6条引物的平均条带共享率为0.8808±0.086，其遗传多样性指数介于2.2120～2.2674之间。 2．四种分子标记与西农萨能奶山羊部分经济性状的关系 2．1 RAPD标记 发现6条对西农萨能奶山羊产奶性能有显著效应的标记条带。特别是标记条带L6I长度为850bp，该标记对总产奶量、第一、第二胎次产奶量的影响均达极显著水平(P＜0.01)。在分析不同基因条带的组合时未发现与各胎次产奶量有显著影响的组合形式。引物OPW19的标记条带OPW19C对西农萨能奶山羊的初生重、体高、体斜长和体重都有显著负效应(P＜0.05)，无该标记条带个体的生长发育显著快于有该标记条带的个体，特别是该标记条带对初生重的影响达极显著水平(P=0.0091)。引物标记条带OPQ05B也显示了对奶山羊胸围及体重的显著负效应(P＜0.05)，无这一标记的个体胸围及体重都显著大于有该标记条带的个体(P＜0.05)。 2．2 PCR-RFLP标记 对56只西农萨能奶山羊β-1g基因(β－乳球蛋白基因)5′侧翼区710 bp (上游588 bp及第一外显子的122 bp)进行PCR-RFLP分析，A等位基因的频率为0.91，B等位基因的频率为0.09，经x~2检验，该基因位点处于Hardy-Weinberg平衡状态(P＞0.05)。β-1g基因5′侧翼区基因型为AA型的个体其各胎次产奶量均比AB型高，其中在第二、三胎次和前四胎总产奶量3项指标上都达显著水平(P＜0.05)。 2．3 PCR-SSCP标记 本试验对56只西农萨能奶山羊к—casein基因(к—酪蛋白基因)第四外显子的基因多态性进行了PCR-SSCP研究，计算出A等位基因频率西农萨能奶山羊部分经济性状的分子标研究为0.6875;B等位基因频率为0.3125。经尤，检验，该基因位点处于Hardy一Weinberg不平衡状态(P<0.肠)。墓因型为AA的个体产奶性能比AB、BB型个体好.其中在第一、第四及总胎次达到了显著水平(P<0.05)。AB型个体和BB型个体之间的差异不显著(乃0，05). 2.4微卫星标记本研究用牛基因组的13对微卫星引物和绵羊的6对微卫星引物扩增西农萨奶山羊的基因组DNA，扩增所得带纹清晰，但所用的19对引物都没有产生多态性。更多还原

【Abstract】 Xinong Saanen dairy goat was breeded by Northwest University using Saanen dairy goat introduced from America and England during the 1920s~1930s. This breed was such characteristic as tall body, good adaptation, stable inheritance and high milk production. In the experiment, the milk production traits were analyzed by RAPD, PCR-RFLP, PCR-SSCP and microsatellite, while birth weight, size and development were analyzed by RAPD. The aim was to discover the hereditary characteristic and to find DNA molecular markers which have effects on milk production and some economic traits as talked above. We hope that both the work and its result can provide data for Xinong Saanen dairy goat and it’s breeding. The main results were as follows:1. The hereditary characteristic of RAPD. 6 primers, selected from 64 random primers, amplified 56 bands; among which 34 bands were polymorphic and its variational rate were 58.6%. From the PCR production of 6 primers, their average bands sharing rate was calculated as 0.8808 ?.086, and polymorphic index was between 2.2120-2.2674.2. Four type of DNA markers and it’s relationship with some economic traits.2.1 RAPD markers: 6 marked bands were found having significant effects on milk production, especially the marker band L6-I (890bp) had a very significant effect (P < 0.05) on the first, second lactation and total milk production. Obvious combining forms were not found between gene band and milk yield. The band OPW19CS had significant effect on birth weight and bodyweight, the goat without the band developed better than the individuals with it, particularly, it’s effect on birth weight is very significant (P < 0.01). Same as this, without the band OPQ05-B, the goat got a bigger heart-girth and body weight than the comparing group.2.2 PCR-RFLP marker: 56 milk goats were analyzed in the experiment. P-lg gene’s 51 flank region(71 Obp) including 588bp of the upstream and 122bp of the exon I, whichwas amplified with PCR-RFLP, two alleles, A ana B were round m the locus. The two genes were in the state of Hardy-Weinberg’s balance with the gene frequency of A:0.91, B:0.09. Goat of AA type showed better milk production in 2nd , 3rd and total lactation than AB type(P < 0.05), no BB type were fount in the experiment.2.3 PCR-SSCP marker: Two new alleles of exon 4 of K -casein were discovered by PCR-SSCP in 56 Xinong Saanen dairy goat. With the A gene frequency of 0.6875 and B: 0.3125 the new alleles were not in the state of Hardy-Weinberg balance. Further analysis and calculation told us: goat with AA type, its milk performance were better than those with AB or BB type. The difference was significant in 1st, 4th and total milk yield (P < 0.05). No clear difference between AB and BB type were detected.2.4 Microsatellite marker: In this experiment 13 and 6 pairs primers of cattle and sheep were used in the PCR reaction of Xinong Saanen goat gnome DNA. The electrophporesis patterns of amplified products were clear, but no polymorphism was attained in the 19 primers.更多还原