我国巴马小型猪SLA-2基因克隆及分子特征

Cloning and Molecular Characterization of the SLA-2 from Bama Miniature Pig

摘要:

为研究我国巴马小型猪SLA-Ⅰ分子特征，设计引物克隆了SLA-Ⅰ类分子SLA-2基因（SLA-2*bm），并通过分子生物学软件分析其分子特征。经克隆及序列测定分析，SLA-2*bm为1119bp，其中3～1097为ORF区，共编码364个氨基酸，分别在第125、188、227和283位置出现半胱氨酸残基，含有两对链内二硫键。氨基酸同源性分析显示SLA-2*bm与其它SLA-2、 SLA-3和SLA-1序列的同源率分别为88.4%～96.4%、88.3%～90.5%和87.7%～92.7%。系统进化树显示SLA-2*bm与其它SLA-2等位基因在遗传关系上相对独立，进化程度较低；各功能区分析，SLA-2*bm与人HLA-A2和小鼠H-2K分子结构相似，且保留了人HLA-A2基因的部分功能位点。结果表明，SLA-2*bm属于一个新的等位基因，巴马小型猪是保留原始基因特征的品种。

Abstract:

In order to study the SLA-Ⅰ molecular characterization of the Bama miniature pig which is an eugenic chinese breed, a pair of primers were designed to amplify the SLA-2 (SLA-2*bm) and then the molecular characterization of the interest gene was analyzed by computer. After cloning, sequencing and analyzing by computer, SLA-2*bm was 1119bp and the ORF frame from 3 to 1097 coded 364 amino acids with two sets of disulfide bond in intro-chain constituted by four cysteines situated in 125, 188, 227 and 283 sites. The amino acid identical ratios between SLA-2*bm and other SLA-2, SLA-3 and SLA-1 alleles were 88.4%～96.4%, 88.3%～90.5% and 87.7%～ 92.7%, respectively. The phylogenetic tree of the SLA-2*bm demonstrated that it was relatively independent to other SLA-2 genes and evolved at low extent. Besides, the SLA-2*bm was similar to the HLA-A2 and H-2K in functional domains and it preserved some functional sites of HLA-A2. The results indicated that SLA-2*bm was a new allele of SLA-2 and the Bama miniature pig might keep down the archaic genetic characterization in China.