娟姗牛催乳素基因型与产奶量的关联性分析

目的]研究娟姗牛催乳素（PRL）基因多态性与产奶量之间的关联性,为选育高产奶量娟姗牛新品系奠定基础.方法]利用PCR-RFLP分析44头娟姗牛PRL基因外显子2和外显子4的多态性,统计不同基因型娟姗牛305 d的平均产奶量,然后分析娟姗牛PRL基因型与产奶量的关联性.结果]娟姗牛PR基因外显子2和外显子4存在RsaI酶切多态性,外显子2有AA和AG两种基因型,外显子4有AA、AG和GG 3种基因型;外显子2和外显子4的AG型频率分别是0.7272和0.5454,为优势基因型.PRL基因两个外显子AA型个体的305 d平均产奶量均高于AG型和GG型（P＞0.05）;基因型组合效应分析发现,A2A2A4G4为优势组合基因型,但在305 d平均产奶量方面是A2G2A4A4组合基因型的产奶量显著高于A2A2A4A4、A2A2A4G4和A2A2G4G4组合基因型（P＜0.05）.结论]娟姗牛PRL基因外显子2和外显子4的碱基突变与产奶量之间存在关联性,其中第8398位碱基A是娟珊牛高产奶量的有利等位基因.

Relation analysis of prolactin genotypes and milk yield of Jersey cow

Objective]The relation between the polymorphism of prolactin （PRL） gene and milk yield of Jersey cow was studied in order to provide references for breeding high-milk-yield cattle.Method]The polymorphism of PRL gene exon2 and exon4 of forty-four Jersey cow were analyzed by PCR-RFLP.The differences in average milk yield of cow with different genotypes were statistically analyzed to elucidate the relation between the polymorphism of prolactin （PRL） gene and milk yield of Jersey cow.Result]There was Rsa I digesting polymorphism among exon2 and exon4 of Jersey cow PRL gene.The exon2 showed two genotypes AA and AG,and exon4 showed three genotypes AA,AG and GG.The genotype AG was dominant in exon2 and exon4 with genotypic frequencies of 0.7272 and 0.5454,respectively.The average 305 d milk yield of Jersey cow with AA genotype was higher than that of those cow with AG or GG （P＞0.05）.Genotypes combination analysis indicated that genotype combination A2A2A4G4 was dominant,while the average 305 d milk yield of Jersey cow with A2A2G4G4 genotypes was significantly higher than that of cow with A2A2A4A4,A2A2A4G4 or A2A2G4G4 genotypes （P＜ 0.05）.Conclusion]The polymorphism of PRL gene and milk yield in Jersey cow was related.The 8398th base A was favorable allele for high-milk-yield Jersey cow.