| 摘要: |
| 【目的】研究奶牛脂肪酸合成酶(Fatty acid synthase，FASN)基因多态性对产奶量和乳成分的影响，为中国荷斯坦牛的优化育种提供相应的分子遗传学依据。【方法】以464头中国荷斯坦牛为研究材料，参照奶牛生产性能测定（Dairy herd improvement，DHI）方法采集产奶量和乳成分数据；采集试验牛血样，提取DNA，PCR扩增FASN基因，用单链构象多态性(Single-strand conformation polymorphism，SSCP)技术并结合测序确定基因型；用最小二乘法进行基因多态性与泌乳性状的关联性分析。【结果】FASN基因外显子34存在2 个等位基因、2种基因型，A、B 等位基因频率分别为0.813 9和0.186 1，试验群体在这一位点上极显著偏离Hardy-Weinberg 平衡状态(P＜0.01)，遗传杂合度(He)和多态信息含量(PIC)分别为0.372 3和0.257 0。测序结果显示，与普通黄牛FASN基因序列(GenBank登录号：AF285607)相比，B 等位基因在第16 024 和16 039 位核苷酸处分别发生了A→G和C→T碱基突变，其中A→G突变导致苏氨酸变成丙氨酸，C→T突变导致精氨酸变为色氨酸；A等位基因与AF285607序列相同。最小二乘法分析表明，AA型个体305 d乳脂量显著高于AB型个体(P＜0.05)，等位基因A为高乳脂量优势基因。【结论】FASN基因外显子34突变位点可作为高乳脂的分子遗传标记应用于中国荷斯坦牛的标记辅助选择育种中。 |
| 关键词: 中国荷斯坦牛 脂肪酸合成酶(FASN)基因 单核苷酸多态性 泌乳性状 |
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| 基金项目:科技部星火计划项目(2008GA860014)；甘肃省重大科技专项（0801NKDP037）；甘肃省生物技术专项(GNSW-2009-08) |
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| Correlation between PCR-SSCP polymorphism of part FASN gene sequence and milk traits in Chinese Holstein cattle |
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MA Yannan,HE Pengjia,MA Yongsheng,et al
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Gansu Normal University for Nationalities,et al
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| Abstract: |
| 【Objective】This study aimed to study the effect of polymorphisms of Fatty acid synthase (FASN) gene on milk yield and milk composition of Chinese Holstein cattle to improve the breeding of Chinese Holstein cattle.【Method】464 improved descendants from Holstein cows and frozen semen of Holstein bull were selected in this study.Milk yield and milk composition information was collected based on DHI production performance measurement.DNA was extracted from the experimental group and genotypes were detected using PCR-SSCP and DNA sequencing.The least squares method was used to analyze the correlation between polymorphisms and milk traits.【Result】There were two alleles and two genotypes in the locus of FASN gene exon 34.The allelic frequencies of A and B were 0.813 9 and 0.186 1,respectively,and the population was not Hardy Weinberg equilibrium at this locus (P＜0.01).Heterozygosity (He) and polymorphism information content(PIC)were 0.372 3 and 0.257 0,respectively.Comparing with sequence of Bos Taurus (Accession #:AF285607),mutations A→G and C→T occurred at the 16 024 bp and 16 039 bp of allele B,respectively.16 024 bp A→G mutation resulted in transformation of Threonine into Alanine,and 16 039 bp C→T resulted in transformation of Arginine into Tryptophan.Allele A was the same as that of AF285607.Least Squares method showed that the milk fat yield for 305 d with genotype AA was significantly higher than that with genotype AB (P＜0.05),indicating that allele A was the dominant gene of high milk fat yield.【Conclusion】FASN gene exon 34 mutations can be used as molecular genetic markers for high milk-fat in marker assisted selection (MAS) for Chinese Holstein cattle breeding. |
| Key words: Chinese Holstein cattle fatty acid synthase (FASN) gene SNP milk traits |
