五指山小型猪生长激素释放激素受体基因的cDNA克隆及序列分析

目的]克隆五指山小型猪生长激素释放激素（GHRH）受体基因的cDNA，并对其进行序列分析。方法]以五指山小型猪耳组织提取的基因纽RNA为模板，根据已报道的猪GHRHRcDNA序列设计3对引物，用RT—PCR方法进行cDNA扩增。PCR产物经回收纯化后，与pMD18-T连接并转化大肠杆菌DH5a，转化产物经PCR和双酶切鉴定后筛选出阳性克隆，阳性克隆经LB液体培养基培养鉴定后测序。结果]成功获得了五指山小型猪GHRH受体基因的cDNA，该片段长1577bp，编码423个氨基酸。BLAST分析结果表明，该片段与猪GHRH受体基因仅有23个碱基的差异，同源性为98％；而两者GHRH受体基因均由423个氨基酸组成，序列同源性为96％。结论]该研究为进一步揭示五指山小型猪的矮小机理提供了理论依据。

Clone and Sequence Analysis on cDNA Growth Hormone Releasing Hormone Receptor Gene from Wuzhishan Miniature Pig

Objective] The study aimed to clone cDNA of GHRH receptor gene from Wuzhishan miniature pig and analyze its sequence.Method] Three pairs of primers were designed according to the sequence of announced GHRH receptor gene of pig.By taken the total RNA from ear tissue of Wuzhishan miniature pig as the template,the specific primers were used to amplify cDNA of GHRH receptor gene by RT-PCR method.The amplified products were connected with pMD18-T and transformed into Escherichia DH-5α,after it was recovered and purified with gel,while the positive clones were taken to conduct sequence analysis after they were cultured by liquid medium of LB.Result] The cDNA of GHRH receptor gene were successfully gained in the test and the length of cDNA fragment was 1 577 bp which coded 423 amino acid.The result of BLAST analysis showed that the fragment had 23basyls which were different from that of pig,so their homology was 98%.The GHRH receptor gene of Wuzhishan miniature pig were all composed by 423 amino acid,and the sequence homology of their GHRH receptor genes was 96%.Conclusion] The experiment provided theoretical basis for further studying on dwarfishness mechanism of Wuzhishan miniature pig.