摘要： 根据GenBank发表的鸭γ-干扰素cDNA基因序列，自行设计、合成1对引物，应用RT-PCR技术，无需用非特异性免疫原如ConA、PHA等刺激分离的脾淋巴细胞，直接提取总RNA，扩增固始鸭γ-干扰素基因(DuIFN-γ)，并进行克隆和测序。测序结果表明，获得了DuIFN-γ全序列，其大小为515 bp，包含一个完整阅读框，编码164个氨基酸残基，推导的氨基酸有3个潜在的N-糖基化位点，有5个与二硫键形成有关的半胱氨酸。序列比较分析发现，克隆的固始鸭IFN-γ基因序列与GenBank中4条鸭IFN-γ基因序列中的3条序列(AF087134，AF100929，AJ012254)完全一致，而与另一条北京鸭核苷酸同源性为99.6%，有2 个碱基发生非同义变异，氨基酸同源性为98.8%。固始鸭与人和其他种动物的IFN-γ基因序列分析和系统进化分析表明，IFN-γ基因存在种属的差异性，亲缘关系越近，同源性越高。DuIFN-γ基因的成功克隆为进一步研究固始鸭IFN-γ基因表达、生物学活性和应用奠定基础。

关键词: 固始鸭, IFN-&gamma, 基因, 克隆, 进化分析

Abstract: One pair of primers was designed according to duck interferon-gamma (IFN-γ) gene sequences published in GenBank, which was used to amplify the IFN-γ gene from total RNA extracted directly from Gushi duck splenocyte without induction of PHA by reverse transcription-polymerase chain reaction (RT-PCR). The gene fragment was then cloned and sequenced. The result showed that the full length of the amplified duck IFN-γ gene sequence was 515 bp, which includes a open-reading frame (495 bp) and encodes 164 amino acid residues. There are three potential N-glycosalation sites and five cysteines in the deduced amino acid sequence. Compared with the duck IFN-γ gene sequences registered in GenBank, the the nucleotide sequence of Gushi duck IFN-γ gene was the same as AF087134, AF100929 and AJ012254, and shared 99.6% homology with Peking duck IFN-γ gene. Based on the gene sequence comparison and phylogenetic tree analysis, the genus difference was found in IFN-γ gene, and the closer the genetic relationship, the higher the homology. This study paved the way for future study of biological function and application of duck IFN-γ gene.

Key words: Gushi duck, IFN-γgene, Cloning, Phylogenetic analysis

中图分类号: 

• Q78