牛AQP7基因第3外显子的单核苷酸多态性与精液品质的相关分析

采用PCR-SSCP技术分析了AQP7基因的第3外显子在西门塔尔和夏洛来群体中的遗传多态性.结果表明在所扩增的AQP7基因的第3外显子中发现PCR-SSCP多态,有2种等位基因A和B,有2种基因型AA型、AB型.对多态片段测序分析表明:在AQP7基因第3外显子中存在有一碱基G→C突变,导致编码氨基酸(精氨酸→苏氨酸)的改变.适合性卡方检验表明该位点的不同基因型频率处于Hardy-Weinberg平衡.用最小二乘法分析AQP7基因第3外显子不同基因型与西门塔尔和夏洛来精液品质的相关性,发现AQP7不同基因型对冻精活精子比率有极显著影响,AA型极显著高于AB型(P<0.01).AA型的冻精项体完整率和冻精活力显著高于AB型(P<0.05),对其他性状的影响差异不显著.研究结果表明,西门塔尔和夏洛来牛AQP7基因应是影响精液品质的一个主效基因或与影响精液品质的主效基因紧密连锁.

Single nucleotide polymorphism in cow exon 3 of aquaporin 7 gene and its association with semen quality

The polymorphism of the exon 3 of aquaporin 7 gene in Simmental and Charolais cattles was analyzed by PCR-SSCP.The results showed that two alleles,A,and B,two genotypes,AA and AB,were detected in the exon 3 of the aquaporin 7 gene.The polymorphism fragments were cloned and sequenced.The sequencing results indicated that there was one single nucleotide mutation:G→C in the exon 3 of the the aquaporin 7 gene.And led to the coding of amino acids(Arg→Thr) had change.The Chi-square test for goodness of fit showed that the frequencies of the aquaporin7 genotypes in the population of Simmental and Charolais cattles agreed with Hardy-Weinberg equilibrium.The genetic correlations were obtained between genotypes of the exon 3 of aquaporin 7 gene and semen quality by the least square analysis.The results indicated that the ratio of live sperm frozen semen for AA genotype on aquaporin 7 was significantly higher than that of AB.And the acrosome integrity of the rate of frozen semen and frozen semen vitality for AA genotype on aquaporin 7 was higher than those of AB(P<0.05).Other traits were not significantly affected.It implied that aquaporin 7 gene should be a major gene or a QTL linked gene which associated with bovine semen quality.