贵州地方猪品种雌激素受体基因内含子1多态性

Polymorphism of Intron 1 in the Estrogen Receptor Gene of Native Pig Breeds in Guizhou Province

为了探索雌激素受体(estrogen receptor,ESR)基因与贵州地方猪品种繁殖性状之间的关系,采用SSCP和RFLP方法,以大约克、外三元杂交猪和梅山猪为对照,对贵州地方猪品种香猪、糯谷猪和柯乐猪ESRα基因进行了多态性分析,共检测到AA、AB和BB 3种基因型,测序结果证实,B等位基因产生的原因是:121 bp扩增片段中第54和57位碱基均突变为C,获得了1个Pvu Ⅱ酶切位点,使AA基因型多出一条带;A等位基因在国外猪品种中占优势,国内猪品种以B等位基因为主,香猪的BB基因型频率最高(79.4%),糯谷猪和柯乐猪均较低(30%、29.8%)。说明贵州地方猪品种的杂合度较高,应加强选育,B等位基因可能与低繁殖率相关。

Estrogen receptors （ESR） are considered as candidate genes for prolificacy traits due to the key role in the regulation of reproductive physiology. Taking Meishan, Large White and three - breed cross （ Duroc x Large white x Landrace） breed as control, the polymorphism of intron 1 in ESRα gene was detected in Xiang, Nuogu, and Kele pig breeds using single strand conformational polymorphism （SSCP） and restriction fragment length polymorphism （RFLP） analysis in the present work. Three genotypes, AA, AB and BB were detected from these populations. Two nucleotide mutations were found at position 54 and 57 in the 121 bp PCR products within intron 1 of ESRα gene, which produced a new Pvu II site in allele B compared with allele A. Further,it was verified that allele A was dominant in the two Euro- pean breeds, whereas allele B was dominant in the native breeds including low fecundity breeds, Xiang pig, Nuogu and Kele pig and the fecund breeds Meishan pig. The frequency of homozygous BB genotype was highest in Xiang pig with 79.4% and only 30% and 29.8% in Nuogu pig and Kele pig breeds, respectively. It suggested that heterozygous de- gree of these native pig breeds in Guizhou Province were high, and allele A of ESRα gene might be a useful marker to improve little sizes of the native pig breeds in Guizhou Province.