【作者】 李丽娟；

【导师】 张利平； 刘武军；

【作者基本信息】 甘肃农业大学 ， 动物遗传育种与繁殖， 2009， 硕士

【摘要】 本研究以220只新疆山羊,305只南疆绒山羊,280只博格达白绒山羊为研究对象,采用PCR-RFLP和PCR-SSCP技术对绒山羊KIFI基因进行单核苷酸多态性检测,探讨KIFI基因在三个品种上的遗传变异多态性。在新疆山羊群体中,运用方差分析和最小二乘拟合线性模型研究KIFI基因多态性与绒细度、绒厚度、产绒量和产绒后体重的相关性。试验所获得结果如下:1.通过PCR-RFLP技术结合测序表明:KIFI基因外显子1处720位存在C跟T的替换,引起氨基酸C→R的变化,为错义突变;内含子1处1020位A→C的突变行成一个HaeIII酶切位点,用HaeIII酶切检测到AA、AC、CC三种基因型,A为优势等位基因,在新疆绒山羊、南疆绒山羊、博格达白绒山羊中的频率分别为0.700、0.729、0.747;KIFI基因外显子3处3212位存在C→T的突变,减少一个HaeIII酶切位点,检测到AA、AB、BB三种基因型,A为优势等位基因,在新疆绒山羊、南疆绒山羊、博格达白绒山羊中的频率分别为0.823、0.777、0.883。此突变没有引起氨基酸的变化,为同义突变。2.通过PCR-SSCP技术结合测序表明:KIFI基因外显子2不存在多态性。KIFI基因外显子4检测到4种基因型,定义为AA、BB、AB和AC型,在.4563位和4699位发现两处突变。4563位C→T的突变,为错义突变,导致氨基酸T→M的改变;4699位A→G的突变,没有引起氨基酸的变化,为同义突变。3.数据分析得知:KIFI基因在3个多态位点上,新疆绒山羊的杂合度都最大,表明选择潜力大。在KIFI-P1基因座,三个品种均表现为中度多态,且都处于Hardy-Weinberg平衡状态;KIFI-P3基因座在南疆绒山羊中表现为中度多态,而在新疆绒山羊和博格达白绒山羊中表现为低度多态,且南疆绒山羊处于非Hardy-Weinberg平衡状态;KIFI-P4两个突变基因座在三个品种中均表现为中度多态,且都处于非Hardy-Weinberg平衡状态。4.对新疆山羊KIFI基因多态性和产绒性状相关性分析表明,在KIFI-P1位点,绒细度最小二乘均值在AA基因型和CC基因型间差异显著(0.01<P<0.05)。推测该突变位点可能是与影响绒细度的一个主效基因或调控因子紧密连锁的分子遗传标记。因此在山羊育种中利用KIFI基因标记辅助选择绒细度是有一定依据的。更多还原

【Abstract】 The experiments was conducted to detect polymorphisms of the goat keratin intermediate-filaments type I (KIF I) gene in three Chinese cashmere goat breeds.Total of 220 Xinjiang goats, 305 Nanjiang cashmere goats and 280 Bogeda Cashmere goats were used in this study. PCR-RFLP,PCR-SSCP and DNA sequencing were used to detect polymorphisms of the goat keratin intermediate-filaments type I (KIF I) gene in three Chinese cashmere goat breeds. At the same time analyzed its associations on cashmere fineness, cashmere thickness, cashmere yield and body weight after combed in Xinjiang cashmere goats.The results as follows:1. The results of PCR-RFLP and DNA sequencing showed: there is a novel C to T mutation in exon1 720bp, The mution caused C changed to R, this is a missense mutation; there is a a novel A to C mutation in intron1 1020bp, which forms a HaeIII endonuclease restriction site. Three unique PCR-RFLP banding patterns (genotypes AA, AC and CC) were found, A allele is advantage allele,the frequencies of the A allele in Xinjiang cashmere goats and Nanjiang,cashmere goats, Bogeda Cashmere goats were 0.700,0.729 and 0.747, respectively.In KIF type I exon3, there is a C to T mution in 3212bp, which reduces a HaeIII endonuclease restriction site, Three unique PCR-RFLP banding patterns (genotypes AA, AC and CC) were found. A allele is advantage allele,the frequencies of the A allele in Xinjiang cashmere goats and Nanjiang, cashmere goats, Bogeda Cashmere goats were 0.823,0.777 and 0.883, respectively. The motion not caused amino acid change, this is a Synonymous mutation.2. The results of PCR-RFLP and DNA sequencing showed: KIF I exon2 has no polymorphism.There were 2 SNP in exon4, the mution C to T in 4563bp was a missense mutation, which caused T changed to M.. The mution A to G in 4699bp was a synonymous mutation, which not caused amino acid change. 3.From the data analysized we know: In three KIFI polymorphism site, heterozygosity in Xinjiang cashmere goat are largest, so the Xinjiang cashmere goat has greatest choice potential.In KIFI-P1 enzyme locus,All breeds showed moderate polymorphism, tests of Hardy-Weinberg equilibrium confirmed that all three breeds were in equilibrium; In KIFI-P3 locus, Xinjiang cashmere goat showed moderate polymorphism, but showed low polymorphism, and Nanjiang cashmere goat was not in Hardy-Weinberg equilibrium; In KIFI-P4 locus, All breeds showed moderate polymorphism in two mutation site, and the genotypic distributions in three cashmere goat breeds were not in Hardy-Weinberg equilibrium.4.The impact of KIFI gene polymorphism on cashmere traits (cashmere fineness, down cashmere thickness, cashmere yield, body weight after combing) in the Xinjiang goats breed were analyzed, the result indicated that: in KIFI-P1 enzyme locus greater cashmere fineness in genotype AA compared to genotype CC ( P < 0.05). Suggesting that this mutation may be a molecular markers that closely linked to a master gene or regulatory factor which impacting cashmere fineness.Therefore,used KIF type I gene genetic marker-assisted selection cashmere fineness has certain basis.更多还原