【作者】 乐祥鹏；

【导师】 雷初朝；

【作者基本信息】 西北农林科技大学 ， 动物遗传育种与繁殖， 2010， 硕士

【摘要】 本研究以708只西农萨能奶山羊和关中奶山羊为试验材料,利用生物信息学、DNA测序、PCR-SSCP、PCR-RFLP和AS-PCR技术,研究了西农萨能和关中奶山羊CSN1S1基因(外显子2、9、12、17、19和内含子14)、CSN1S2基因(外显子2、3、9、11、16)共2个候选基因11个基因位点的遗传变异,同时探讨这两个奶山羊品种遗传多态性与奶山羊体尺性状(体高、体长、胸围)、产奶量和奶成分(奶蛋白、奶脂肪、总乳固体、非脂固形物、乳糖、乳密度)的关系,旨在获取与经济性状相关的分子遗传标记,为奶山羊遗传资源的保护、开发与利用提供科学依据。本研究获得以下重要研究结果:1、CSN1S1基因的遗传变异及其与奶山羊经济性状的关系在西农萨能奶山羊、关中奶山羊品种中检测了CSN1S1基因6个基因位点(P1～P6)的多态性。在CSN1S1基因的6个基因位点中,在P2和P6基因位点上分别发现1bp (C)和7bp (TTATCTA)的缺失,在P3位点上验证了前人发现的突变,而在P1、P4和P5位点上没有发现多态。①在CSN1S1基因P2基因位点检测到三种基因型:AA、AB和BB,其中西农萨能和关中奶山羊A/B等位基因的频率分别为0.198/0.802, 0.361/0.639;西农萨能和关中奶山羊在P2位点均为中度多态(0.25<PIC<0.50),并处于Hardy-Weinberg不平衡状态;P2位点的各基因型在西农萨能和关中奶山羊品种间的分布差异极显著(P<0.01)。②P3基因位点仅在关中奶山羊品种上表现为多态,检测到两种基因型:A01和AA,其中等位基因A和01的频率分别是0.960和0.040;关中奶山羊在该位点为低度多态(PIC=0.073),处于Hardy-Weinberg平衡状态。③在P6位点上也检测到三种基因型:CC、CT和TT,其中等位基因C/T的频率在西农萨能和关中奶山羊品种中分别为0.888/0.112和0.763/0.237;西农萨能奶山羊品种在该位点处于低度多态(PIC=0.179),而关中奶山羊品种在该位点处于中度多态(PIC=0.297),两个品种在该位点都处于Hardy-Weinberg非平衡状态;P6位点的各基因型在西农萨能和关中奶山羊品种间的分布差异极显著(P<0.01)。④联合分析P2和P6位点可以鉴定CSN1S1基因的F和N等位基因,关中奶山羊和西农萨能奶山羊品种中的F/N等位基因频率为0.1139/0.0927和0.2376/0.1193, N和F各基因型在两个奶山羊品种中分布差异显著(P<0.05)。多态基因位点与奶山羊经济性状的关联分析表明:①P2基因位点显著的影响关中奶山羊的体长,AB型个体的体长显著的高于AA和BB型(P<0.05);P2基因位点对西农萨能奶山羊品种的第一胎产奶量影响显著,AA和AB型个体的第一胎产奶量显著的高于BB型个体(P<0.05)。②在P6基因位点,关中奶山羊CC基因个体的胸围显著低于TT和CT型(P<0.05);西农萨能奶山羊CT和TT型个体的第一胎产奶量分别极显著(P<0.01)和显著(P<0.05)的高于CC型。③关中奶山羊FF基因型个体的胸围明显比FN、FO、NO和NN基因型高(P<0.05);西农萨能奶山羊NN基因型个体乳中蛋白含量极显著的低于其他基因型个体(P<0.01);西农萨能奶山羊FF基因型个体第一胎奶产量显著的高于NO基因型个体(P<0.05)。2、CSN1S2基因的遗传变异及其与奶山羊经济性状的关联对西农萨能和关中奶山羊品种CSN1S2基因5个基因位点的研究发现,仅L2位点表现多态。试验证明在目前已发现的7种CSN1S2等位基因中,本试验研究的品种只存在A和F等位基因。西农萨能和关中奶山羊群体品种中A/F等位基因的频率分别为0.795/0.205和0.739/0.261,两个品种在L2位点均为中度多态(0.25<PIC<0.50)。关中奶山羊品种在该位点处于Hardy-Weinberg非平衡状态,西农萨能则处于Hardy-Weinberg平衡状态。不同奶山羊品种间CSN1S2基因L2多态基因位点基因型分布的卡方独立性检验结果显示:西农萨能与关中奶山羊品种之间显著(P<0.05)。多态基因位点与奶山羊经济性状的关联分析表明:L2基因位点对西农萨能奶山羊的奶成分影响显著,FF基因型个体乳中脂肪和总乳固体的含量均显著的高于AA和AF基因型个体(P<0.05)。更多还原

【Abstract】 To obtain molecular genetic marker related to economic traits in dairy goats, the genetic variations of 11 loci from CSN1S1(exon 2, 9, 12, 17, 19 and intron 14) and CSN1S2 (exon 2, 3, 9, 11, 16) genes and their associations with body size (withers height, body length and heart girth), milk yield, and milk composition (fat, protein, lactose, total solids, solids-not-fat and density) traits in 708 samples of Xinong Sannen (XS, n=440) and Guanzhong (GZ, n=268) breeds were analyzed using bioinformatics, DNA sequencing, PCR-SSCP,PCR-RFLP and AS-PCR techniques. The important results were in the followings:1. Genetic variation of CSN1S1 gene and their assosiations with economic traits in dairy goatsThe varations of six loci (P1~P6) in CSN1S1 gene were studied in populations of XS and GZ. In these six loci, one nucleotide (C) and seven nuleotides (TTATCA) deletions were detected in P2 and P6 locus respectively, as well as P3 locus, the same mutation was found as the previously published result, while no polymorphisms were detected in P1, P4 and P5 locus.①There were three genotypes in the P2 locus of CSN1S1 gene: AA,AB and BB. The frequences of A/B allele were 0.198/0.802 and 0.361/0.639 in XS and GZ breeds respectivelyAt the P2 locus, both of the populations were moderate polymorphic (0.25<PIC<0.50) and not in the agreement of Hardy-Weinberg equilibrium. Theχ2 test of the genotype distributions showed that there was significant difference between the two populations (P<0.01).②The polymorphism of P3 locus was only detected in GZ population. Two genotypes, AA and A01 were found. GZ population was low polymorphic (PIC=0.073) and in the agreement of Hardy-Weinberg equilibrium.③Three genotypes, CC, CT and TT were detected at the P6 locus of CSN1S1 gene. Allelic frquences of C/T were 0.888/0.112 and 0.763/0.237 in XS and GZ population respectively. XS population was low polymorphic (PIC=0.179), while GZ population was moderate polymorphic (0.25<PIC<0.50). Neither of the populations were in the agreement of Hardy-Weinberg equilibrium. Theχ2 test showed that the genotype distributions in GZ and XS populations were significantly different in P6 locus (P<0.01).④While comprehensively analyzing P2 and P6 locus can identify CSN1S1 N and F alleles. The frequences of N/F allele were 0.0927/0.1139 and 0.1193/0.2376 in XS and GZ population respectively. Theχ2 test showed that the genotype distributions in GZ and XS populations were significantly different (P<0.05).The GLM analysis result between every polymophic locus and eonomic traits in the GZ and XS population showed that:①The different genotypes of P2 locus significantly affect body length and first lacation milk yield in GZ and XS population. Individuals of AB genotype have advantage body length than AA and BB genotypes in GZ population(P<0.05), while individuals of AA and AB genotypes have better record than BB genotype in the first lacation milk yiled in XS population (P<0.05).②At the P6 locus, the body height of GZ individuals containing CC genotype is significant lower than TT and CT genotypes (P<0.05), while individuals exhibiting TT and CT genotypes have more volume of milk yield than CC genotype in XS population (P<0.01, P<0.05).③Individuals of FF genotype get significant larger heart girth than FN, FO, NO and NN genotypes in GZ population (P<0.05), and their volume of the first milk yield is significant higher than NO genotype in XS population. The NN genotype contained signiciant lower protein content than other genotypes in XS population (P<0.01).2. Genetic variations of CSN1S2 gene and their assosiations with economic traits in dairy goatsAccording to five loci (L1～L5) detected in CSN1S2 from GZ and XS population, the polymorphism was only detected at the L2 loucs in this study. The results indicated that there were A and F alleles in XS and GZ population, which were the two alleles from seven existing alleles in CSN1S2 gene until now. Allelic frequences of A/F were 0.795/0.205 and 0.739/0.261 in XS and GZ population respectively. Both of the populations were moderate polymorphic (0.25<PIC<0.50) at the L2 locus. XS population was in the agreement of Hardy-Weinberg equilibrium, neither was GZ population. Theχ2 test of the genotype distributions showed that there was significant difference between the two populations (P<0.05).The results of the association of polymorphisms with economic traits showed that: L2 locus significantly affect milk composition in XS population, the individuals of FF genotype have better milk fat and total soild than AA and AF genotypes (P<0.05).更多还原