草原红牛二酞甘油酞基转移酶2(DGAT2)基因的多态性及与泌乳性状关联性分析

Polymorphism of diacylglycerol acyltransferase 2 gene and its associations with milk performance traits in red steppe

为研究草原红牛二酞甘油酞基转移酶2(DGAT2)的多态性及与泌乳性状相关性,采用PCR-RFLP方法检测DGAT2基因的遗传多态性。结果检测到AA、AB和BB 3种基因型,统计分析表明该多态位点与草原红牛乳中脂肪和干物质含量呈显著相关,脂肪:AA型极显著高于AB型和BB型(P<0.01),AB型和BB型之间差异不显著(P>0.05);干物质:AA型显著高于AB型(P<0.05),极显著高于BB型(P<0.01),而AB型又显著高于BB型(P<0.05);其他泌乳性状的基因型间差异不显著(P>0.05)。此结果提示,DGAT2基因对草原红牛乳中脂肪和干物质含量具有较大的遗传效应,可以初步推断DGAT2是控制这些性状的众多基因之一,可能是影响草原红牛乳中脂肪和干物质含量的一个主效基因或与主效基因相连锁,可作为选育草原红牛低脂及高干物质奶牛的分子标记,用于标记辅助选择意义重大。

This study was designed to investigate the single nucleotide polymorphism （SNP）of diacylglyeerol acyltransferase 2 （DGAT2） gene in red steppe by PCR RFLP, and analyze the correlation between the polymorphisms and milk performante traits. The result of PCR- RFLP indicated that there were three genotypes（AA, AB and BB）. The correlation analysis showed that polymorphism had a extremely significant effect on milk fat and dry matter, the cows with AA genotype had higher milk fat than the AB and BB genotype （P〈0.01）, but there was no significant difference between AB and BB geno-type（P〉0.05）. For the dry matter, the AA genotype was higher than the AB and BB genotype （P〈0.05）, the AB geno-type was higher than the BB genotype （P〈0.05）. Other milk performance traits of red steppe was not different between different genotypes （P〉0.05）. It could be preliminarily concluded that DGAT2 gene was probably a major gene or a QTL linked gene which is associated with milk fat and dry matter and can be chosen as the molecular markers of choosing low milk fat and high dry matter in red steppe.