湖南沙子岭猪SLA-DR基因克隆及生物信息学分析

Cloning and bioinformatics analysis of SLA-DR genes in Hunan Shaziling pigs

为了克隆湖南沙子岭猪SLA-DRA和SLA-DRB基因,分析SLA基因特性和抗原多态性,评价湖南沙子岭猪在异种移植中的应用前景奠定基础。应用RT-PCR分别扩增湖南沙子岭猪SLA-DRA和SLA-DRB基因,鉴定后克隆到PUCm-T载体并进行测序,用NCBI中的BLAST和ExPASY中相关软件进行生物信息学分析。得到的湖南沙子岭猪SLA-DRA和SLA-DRB基因特异性基因片段,大小分别为1 177 bp和909 bp。生物信息学分析发现,所扩增的SLA-DRA和SLA-DRB基因片段均包含完整的开放阅读框,分别编码252和266个氨基酸残基。将湖南沙子岭猪SLA-DRA和SLA-DRB基因在GenBank登录,登录号分别为EF143987和EF143988。同源性分析发现,湖南沙子岭猪SLA-DRA和SLA-DRB与人类相应的DRA、DRB相比,核苷酸序列同源性分别为83%和83%,编码氨基酸同源性分别为83%和79%。与GenBank登录的其他猪种相比,SLA-DRA基因同源性最高可达100%,而SLA-DRB基因具有多态性。

In order to clone class II DRA and DRB genes of swine leukocyte antigen （SLA） in Hunan Shaziling pigs, to analyze their characteristics and polymorphism and to provide immunological basic parameters for xenotransplantation from pigs to humans. SLA-DRA and SLA-DRB genes in two Shaziling pigs with the absence of porcine endogenous retrovirus （PERV） env-c were amplified by RT-PCR, cloned into PUCm-T vectors, sequenced and analyzed through BLAST in NCBI and related software in ExPASY. The obtained SLA-DRA and SLA-DRB genes of Shaziling pigs were 1 177 and 909 nucleotides in length with their accession numbers in Genbank as EF143987 and EF143988. Bioinformatics analyses have shown that they both contain opening reading frame （ORF） and encode 252 and 266 amino acids respectively. Comparing the ORF and protein sequences of the Shaziling SLA-DRA and SLA-DRB genes with their counterpart sequences of human, the homologies of nucleotide sequences were 83% and 83%, and the homologies of amino acid sequences 83 % and 79% respectively. Further comparison with SLA sequences published in GenBank indicated that SLA-DRB gene found in Shaziling pigs has polymorphism while the homology of SLA-DRA gene is up to 100 %.