藏猪生长激素（pGH）基因多态性研究

猪生长激素（pGH）是猪生长发育性状重要的候选基因之一。采用PCR RFLP技术检测藏猪pGH基因+159～+734 bp片段的Dra I、Apa I和Msp I酶切多态性。结果显示，藏猪群体中Dra I酶切全部切开，无多态；Apa I酶切具有4个等位基因，出现5种基因型，其中CC基因型（299A/432C）频率最高，为0.7857；藏猪群体Msp I酶切出现3种基因型，杂合性CT基因型频率最高，为0.5089，等位基因C和T频率分别为0.5580和0.4420。经比较，藏猪pGH基因Dra I酶切位点与其他猪种一样无多态性，而Apa I酶切出现了特异的432突变位点，Msp I酶切等位基因分布相对均衡，表现出与其他猪种的差异。

Polymorphisms of the Porcine Growth Hormone (pGH) Gene in Tibet Pig

The porcine growth hormone (pGH) gene is one of important candidate for development and growth trait. In the present study, the polymorphism of fragment +159~+734 of pGH gene was measured with the methods of PCR RFLP by restriction endonuclease Dra I, Apa I and Msp I. The results showed that the Tibet pig has no diversity for PCR Dra I RFLP of pGH gene. There are four alleles and five genotypes for PCR Apa I RFLP of pGH gene, and the genotype CC (299A/432C) is predominant (0.7857). The Tibet pig population has three genotypes for PCR Msp I RFLP of pGH gene, and the predominant genotype CT is (0.5089). The frequencies of allele C and allele T are 0.5580 and 0.4420 respectively. By comparing with other breeds, the Tibet pig has differential genotypes for Apa I, and the distribution of alleles for Msp I is uniform relatively, which may be the difference of Tibet pig with other pig breeds.