中国西门塔尔牛MAT2B基因多态性及其与肉品质性状的关联分析

Polymorphism analysis of MAT2B gene and correlation with meat quality traits in Chinese Simmental cattle

为了研究中国西门塔尔牛甲硫氨酸腺苷转移酶2B(Methionine adenosyltransferase 2B,MAT2B)基因的多态性及其与肉品质性状的关系,试验采用DNA测序技术和PCR-RFLP方法对127头中国西门塔尔牛MAT2B基因的多态性进行研究,并通过SPSS 23.0软件分析其与肉品质性状的相关性。结果表明:电泳得到的条带明亮、清晰,无引物二聚体、抹带和非特异性扩增条带,大小为933 bp。在中国西门塔尔牛群中,MAT2B基因存在1个位于第2内含子5'端的第2382个碱基的多态性位点,即I2-2382 G>T位点。该位点属于中度多态,且处于Hardy-Weinberg平衡状态。该位点存在GG、GT、TT 3种基因型,GG基因型个体的肾脏脂肪、屠宰酸度、胴体深、胴体胸深显著高于TT基因型(P<0.05),腰部肉厚显著低于TT基因型(P<0.05),胴体长显著高于GT基因型(P<0.05);GT基因型个体的屠宰率显著高于TT基因型(P<0.05)。说明MAT2B基因的I2-2382 G>T位点可作为中国西门塔尔牛肉品质性状的相关分子标记。

In order to study the polymorphism of the methionine adenosyltransferase 2 B(Methionine adenosyltransferase 2 B, MAT2 B) gene in Chinese Simmental cattle and its relationship with meat quality traits, the polymorphism of MAT2 B gene in 127 Chinese Simmental cattle was studied by using DNA sequencing and PCR-RFLP. The correlation between the MAT2 B gene and the meat quality traits was analyzed by SPSS 23.0. The results showed that the length of the bright and clear PCR production was 933 bp which hasn’t unprimed dimer, wipe band, and non-specific amplification band. A polymorphism site of the MAT2 B gene which was located in 2 382 bp of the 5’ end of intron two was found in Chinese Simmental cattle. The site called I2-2382 G>T was moderately polymorphic and in the state of Hardy-Weinberg and have GG, GT, and TT three genotypes. The kidney fat, slaughter acidity, carcass depth, and carcass chest depth of the GG genotype were significantly higher than the TT genotype(P<0.05). Also, the waist meat thickness was significantly lower than the TT genotype(P<0.05), and carcass length was significantly higher than the GT genotype(P<0.05). The slaughter rate of the GT genotype was significantly higher than the TT genotype(P<0.05). It is suggested that the I2-2382 G>T site of the MAT2 B gene can be used as a molecular marker for beef quality traits of Chinese Simmental cattle.