中国美利奴羊H-FABP基因多态性及其与部分肉质性状的相关性

Single Nucleotide Polymorphism of H-FABP Gene and Its Correlation with Meat Quality Traits in Merino Sheep

利用聚合酶链式反应-单链构象多态(PCR-SSCP)技术检测中国美利奴羊(Ovis aries var.Merino)心型脂肪酸结合蛋白基因(H-FABP)外显子2的单核苷酸多态性(SNPs)和遗传多态性,分析其与肌内脂肪(IMF)含量、肌纤维直径和肌纤维密度的相互关系,为该品种绵羊的分子标记辅助选择提供理论依据。结果显示,H-FABP基因外显子2有AA、AB和BB 3种基因型,AA型和BB型在778位均发生了C缺失,939位均发生了A→G转换,BB型还在789位发生了T→C转换,该突变导致所编码氨基酸发生了缬氨酸→丙氨酸的替换;BB型为IMF的优势基因型,与AB型相比差异显著(P<0.05),与AA型相比差异极显著(P<0.01);BB型对肌纤维直径存在负相关。结果提示,中国美利奴羊H-FABP基因外显子2具有多态性,该基因可能是中国美利奴羊肉质性状的主效基因,或者与控制肉质性状的主效基因相连锁。

In order to analyze the single nucleotide polymorphisms （SNPs） in the extron 2 of heart fatty acid binding protein gene （H-FABP） and its relationship with some meat quality traits in Merino Sheep （ Ovis aries vat. Merino ）, and to provide a theoretical foundation for the marker-assisted selection, we measured intramuscular fat （IMF） content, muscle fiber diameter and muscle fiber density of 150 Merino sheep, and used polymerase chain reaction-single strand conformation polymorphism （PCR-SSCP） technique to analyze the SNPs at the exon 2 of the H-FABP gene. It was shown that the exon 2 of H-FABP gene displayed AA, AB and BB genotypes. There were mutation of 939（A/G） and deletion of C in both AA and BB genotypes, and 789 （T/C） in BB genotype, which led to vallne convertion to alanine. The BB genotype was advantageous genotype of IMF and there were significant difference between BB and AB （P 〈 0.05 ）, and extremely significant difference （P 〈0. 01 ） between BB and AA. The correlation of BB genotype and muscle fiber diameter was negative. These results indicate that the exon 2 of H-FABP gene of Merino Sheep shows polymorphism and that H-FABP gene may be a major gene or a major gene-linked gene for meat quality of Merino Sheep.