鸡IL-18成熟蛋白基因的克隆及分子进化分析  

Cloning and phylogenetic analysis of mature interleukin-18 gene in AA chicken

作　　者：王振国[1] 金宁一[1] 张洪勇[1] 尹革芬[1] 葛淑敏[1] 

机构地区：[1]解放军军需大学研究所,解放军基因工程重点实验室,长春130062

出　　处：《生物技术通讯》2004年第2期135-137,共3页Letters in Biotechnology

摘　　要：根据已发表的鸡白介素18(IL-18)基因序列设计合成引物,以植物凝集素(PHA)和脂多糖(LPS)激活的AA肉鸡脾细胞mRNA为模板,通过RT-PCR扩增出编码鸡IL-18成熟蛋白的cDNA。将该cDNA克隆于pUCm-T载体,并对其进行测序,结果表明所克隆的核苷酸片段包含了全部成熟蛋白编码基因,成熟蛋白编码区507个核苷酸,编码169个氨基酸。把该基因编码的鸡成熟IL-18蛋白氨基酸序列与已公布的禽及哺乳动物IL-8成熟蛋白基因氨基酸序列进行比较,其同源性分别在96.5%～100%和20.1%～26.6%之间。分子系统进化树分析表明鸡IL-18与哺乳动物IL-18有共同的祖先,亲源关系较近,但在免疫系统选择性压力下,形成独特的种族特异性。鸡IL-18基因的克隆为体外表达鸡IL-18蛋白及作为免疫佐剂应用于预防接种的研究奠定了基础。In this study, specific primers for chicken IL-18 cDNA had been designed and synthesized according to the published nucleic acid sequence of chicken IL-18 cDNA. The cDNA encoding chicken mature IL-18 was amplified by RT-PCR from RNA of chicken splenocytes stimulated with phytohemagglutinin and lipopolysaccharide. PCR product was cloned into pUCm-T vector and then was sequenced. The cloned fragment covered the whole mature IL-18 gene(507bp) and encoded 169 amino acids. The results of comparative sequence analysis indicated that putative amino acid sequence of the cloned IL-18 gene shared 96.5%～100% homology with IL-18 of chicken and turkey, and shared 20.1%～26.6% homology with mammalian IL-18. Phylogenetic tree analysis indicated that the chicken IL-18 have evolutionary relationship with mammalian IL-18, however they showed species difference in function because of selective pressure of immune systems. This study have paved the way for farther studying the expression and function of IL-18 as vaccine adjuvants

关 键 词：鸡IL-18 鸡白介素18 基因序列 克隆 分子进化 

分 类 号：Q78[生物学—分子生物学] Q51