牦牛、犏牛乳中β-乳球蛋白多态及表达差异

The genetic polymorphism and content ofβ-lactoglobulin in milk of yak, cattle-yak and dairy cattle

采用聚丙烯酰胺凝胶电泳(PAGE)对麦洼牦牛(包括半奶牦牛)、犏牛及黑白花奶牛乳中β-乳球蛋白(β-LG)遗传变异体进行分析,结果显示β-LG在牦牛、半奶牦牛中BE型占优势,有少数EE型,没有发现A基因.犏牛中BE型占优势,有少数AB型.黑白花奶牛中AB型占优势有AA型,BB型、AB型。没有E基因.用酶联免疫方法测定牛乳中β-LG含量,在不同品种牛中存在总量和各基因型间的差异.各基因在不同牛种的表达存在着差异.

Genetic variants of β-lactoglobulin(β-LG) are investigated in yak, half-lactating yak, cattle-yak and Chinese-Holstein by PAGE. The dominant genotypes of β-LG are BE in yak and half-lactating yak, however, no A genotype. The dominant genotypes of β-LG are BE in cattle-yak, AB in Chinese-Holstein. Meanwhile, genotype of β-LG with three bands of AA, BB and AB are observed in Chinese-Holstein, but there is no E genotype. The content of β-LG in milk is determined by ELASA. There are some differences between total content and genotypes in yak, cattle-yak, half-lactating yak and Chinese-Holstein. We also can see the different expression of genotypes.