牦牛DGAT1基因多态性及其与乳质性状关联分析

发布时间：2018-05-22 12:05

本文选题：牦牛 + DGAT基因　；参考：《中国农业科学》2017年16期

【摘要】：【目的】检测牦牛DGAT1基因多态性,评估基因突变对牦牛乳品质性状的影响,以期丰富牦牛重要经济性状的分子遗传研究基础。【方法】采用PCR-SSCP方法,检测甘南牦牛、天祝白牦牛、青海牦牛及野血牦牛DGAT1基因intron5-exon7和intron15-exon17区突变,分析基因突变对乳品质性状的影响。【结果】牦牛DGAT1基因intron5-exon7区发现c.562+32_c.562+33ins CCGCCC的插入/缺失,等位基因M、基因型MM频率最高为优势等位基因和基因型,各类群牦牛PIC0.5属中度或低度多态;intron15-exon17区检测到c.1249-23CT和c.1336CT的突变,其中exon17发现的c.1336CT突变导致编码氨基酸p.Arg447Cys转变,等位基因A频率最高为优势等位基因,甘南牦牛、天祝白牦牛和青海牦牛中基因型AA为优势基因型,野血牦牛基因型AB为优势基因型,各类群牦牛0.25PIC0.5属中度多态;两区域3处突变位点构建出6种单倍型和11种单倍型组合,突变位点间存在连锁关系且接近于连锁平衡。关联分析表明,甘南牦牛intron5-exon7区基因型与乳质性状无显著相关;intron15-exon17区基因型BB个体乳品质性状最低,且乳蛋白率、乳脂率、总固体物质含量中显著低于其他基因型个体(P0.05);携带等位基因A的个体乳蛋白率、乳脂率、总固体物质含量及无脂固体含量显著高于未携带者(P0.05),携带等位基因C的个体乳脂率也显著高于未携带者(P0.05),而携带等位基因B的个体乳脂率、总固体物质含量显著低于未携带者(P0.05);单倍型组合H1H3个体的乳蛋白率、乳脂率、总固体物质含量和无脂固体物质含量均较高,且乳脂率及总固体物质含量显著高于其他单倍型组合(P0.05),而H2H2单倍型组合个体则较低,除乳糖率以外的其他乳品质性状均显著低于其他7种单倍型组合(P0.05)。【结论】牦牛DGAT1基因intron5-exon7和intron15-exon17区为低度和中度多态,intron6存在c.562+32_c.562+33ins CCGCCC的插入/缺失,intron15和exon17分别检测到c.1249-23CT突变和c.1336CT的非同义突变。intron15-exon17区突变影响甘南牦牛乳品质性状,选留携带等位基因A的个体和淘汰携带等位基因B的个体、或选留H1H3单倍型组合及淘汰H2H2单倍型组合个体,均可显著改善后代群体的乳品质。
[Abstract]:[objective] to detect the polymorphism of yak DGAT1 gene and evaluate the effect of gene mutation on milk quality traits of yak, in order to enrich the molecular genetic basis of important economic traits of yak. [methods] PCR-SSCP method was used to detect Gannan Yak. The intron5-exon7 and intron15-exon17 region mutations of DGAT1 gene in Tianzhu white yak, Qinghai yak and wild blood yak were analyzed. [results] the insertion / deletion of c. 562 32_c.562 33ins CCGCCC was found in intron5-exon7 region of DGAT1 gene of yak. The highest frequency of alleles (M) and genotype (MM) were dominant alleles and genotypes. The mutations of c.1249-23CT and c.1336CT were detected in the middle or low degree polymorphism intron 15-exon17 region of PIC0.5, and the c.1336CT mutation detected by exon17 resulted in the transformation of amino acid p.Arg447Cys. The highest allele A frequency was the dominant allele, the genotype AA was the dominant genotype in Gannan yak, Tianzhu white yak and Qinghai yak, the wild blood yak genotype AB was the dominant genotype, and the 0.25PIC0.5 was moderately polymorphic. Six haplotypes and 11 haplotypes were constructed at 3 mutation sites in the two regions. Correlation analysis showed that there was no significant correlation between genotype of intron5-exon7 region and milk quality traits of Gannan Yak. BB genotype of intron 15-exon 17 region had the lowest milk quality traits, and milk protein rate and milk fat rate were the lowest. The percentage of milk protein and milk fat of individuals with allele A was significantly lower than that of other genotypes. The content of total solids and lipid free solids was significantly higher than that of non-carriers, and the milk fat rate of individuals carrying allele C was significantly higher than that of non-carriers, while the rate of milk fat of individuals carrying allele B was significantly higher than that of individuals with allele B. The percentage of milk protein, milk fat, total solid matter and lipid free solid matter in haplotype combination H1H3 were higher than those in non-carrier group. The milk fat percentage and total solid matter content were significantly higher than those of other haplotype combinations (P 0.05), while those of H2H2 haplotype combinations were lower than those of other haplotype combinations. The milk quality traits except lactose rate were significantly lower than those of the other 7 haplotypes. [conclusion] the intron5-exon7 and intron15-exon17 regions of the DGAT1 gene of yak were low and moderate polymorphic intron6, and the insertion / deletion of c 562 32_c.562 33ins CCGCCC intron15 and exon17 were detected respectively. The non-synonymous mutation of c.1249-23CT and c.1336CT. Intron 15-exon 17 mutation affected milk quality traits of Gannan Yak. Selection of individuals carrying allele A and those with allele B, or H1H3 haplotypes and H2H2 haplotypes, could significantly improve the milk quality of progeny populations.
【作者单位】：甘肃农业大学动物科学技术学院/甘肃省草食动物生物技术重点实验室;甘南州畜牧科学研究所;
【基金】：国家自然科学基金(31160451) 甘肃省农业生物技术研究与应用开发项目(GNSW-2013-9及GNSW-2016-29) 甘肃省杰出青年科学基金(1210RJDA008)
【分类号】：S823.85

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