美系大白猪雌激素受体基因的多态性分析

雌激素受体（estrogen receptor，ESR）能调控雌激素的合成，影响繁殖性能。试验采用PCR-RFLPs技术分析了上海市种猪场关系大白猪核心群的ESR基因的多态性，采用SAS统计分析软件分析了其多态性与母猪繁殖性能的相关性。结果表明：①群体中ESR基因的A和B等位基因的频率分别为39．66％和60．34％。②初产胎次中，BB基因型的总产仔数（TNB）与AA基因型和AB基因型的差异均达到显著水平（P〈0．05）；BB基因型的产活仔数（NBA）与AA基因型的差异达到显著水平（P〈0．05）；BB和AA纯合子间TNB和NBA分别相差2．82和2．28头。③经产胎次，BB基因型的总产仔数（TNB）和产活仔数（NBA）与AA基因型和AB基因型的差异均达到显著水平（P〈0．05）；对于母猪每窝的TNB和NBA，BB纯合子比AA纯合子分别多1．79和2．39头。无论初产胎次或经产胎次，ESR位点的总产纾数和产活仔数都呈现AA〈AB〈BB趋势；ESR基因型的影响在初生窝重和21日龄窝重之间的差异不显著（P〉0．05）；但是以上2个性状在ESR基因的3种基因型间存在BB〉AB〉AA的趋势。以上结果说明，这个种猪群的总产仔数和产活仔数偏高，这与其ESR基因的有利基因B频率较高、AB型和BB型个体多正好吻合．因此可应用分子标记辅助选择（MAS）的方法来提高母猪的繁殖性能．

Analysis of Polymorphisms on Estrogen Receptor Gene in American Large White Pigs

Estrogen receptor （ESR） can regulate the synthesis of oestrogen and affect the reproduction of swine. The polymorphism of ESR gene loci in American Large White from nucleus herd of Shanghai Pig Breeding Farm was investigated by PCR-RFLPs. The association between the polymorphism of ESR gene and the reproduction performance of sows was also analyzed by SAS software. It was observed that the frequencies of A and B alleles of ESR gene in the herd were 39.66% and 60.34%. The results showed that the total number born（TNB） had significant difference between BB and AA genotype as well as between BB and AB genotype （P〈 0.05）, and there was significant difference between BB and AA genotype in the number born alive（NBA） （P〈 0.05） in first parity. In latter parities, TNB and NBA had significant difference between BB and AA genotype as well as between BB and AB genotype（P〈 0.05）. TNB and NBA of the BB genotype had 2.82 and 2.28 more pigs per litter than those of AA genotype in first parity and 1.79 and 2.39 more pigs per litter than AA genotype in latter parities. It had an inclination of the TBN and NBA between these 3 genotypes that was BB 〉 AB 〉 AA both in first and latter parity. There were no detectable effeets on birth weight of litter （BWL） and 21days weaning weight of litter （WWL21） by the genotype. But there was an inclination of BB 〉 AB 〉 AA for the above two traits in these 3 genotypes. So the reproduction performance of sows can be improved by marker assisted selection （MAS）.