藏獒犬α-干扰素全基因的克隆与序列分析

Cloning and sequence analysis of interferon-α gene of Zangao canine

根据GenBank发表的犬α-干扰素（IFN-α）基因核酸序列（AB102731），设计并合成1对引物，利用PCR技术从藏獒犬肝脏基因组DNA中扩增犬α-干扰素全基因，并进行克隆和测序。结果表明，获得了犬IFN-α全基因序列，其大小为564bp，包含1个完整阅读框，编码187个氨基酸残基。序列比较分析发现，克隆的藏獒犬IFN-α基因序列与GenBank中5条犬IFN-α基因序列核苷酸同源性在96．8％～99．3％之间，氨基酸同源性在94．7％-98．9％之间，并无插入和缺失变异，但是存在氨基酸点变异。藏獒犬与人和其他8种动物的IFN-α基因序列分析和系统进化分析表明，IFN-α基因存在种属的差异性，亲缘关系越近，同源性越高。犬IFN-α基因的成功克隆为进一步研究藏獒犬IFN-α基因表达、生物学活性和应用奠定基础。

One pair of primers was desi （IFN-α） nucleic acid sequence （AB102731 ed and synthesized according to the canine interferon alpha gene published in the GenBank. Canine IFN-α gene was amplified by PCR from genome DNA extracted directionally from liver of Zangao canine, then cloned and sequenced. The result showed the full length sequence of Zangao canine IFN-α gene was consisted of 564 bp, which includes one openreading frame, encoding 187 amino acid residues, three potential N-glycosalation sites and ten cysteines in deduced amino acid sequence. The results of comparative sequence analysis and phylogenetic tree analysis showed there was difference of genus in IFN-α gene, the nearer relationship, the higher homology. This study set a basis the way for future study of biological function and application of canine IFN-α.