应用RACE法克隆鸽恒定链基因的研究  

Cloning of pigeon invariant chain (Ii) gene by RACE

作　　者：刘岗[1] 仲大莲[1] 刘雪兰[1] 余为一[1] 

机构地区：[1]安徽农业大学安徽省人兽共患病重点实验室,合肥230036

出　　处：《遗传》2008年第1期77-80,共4页Hereditas（Beijing)

基　　金：国家自然科学基金项目(编号:30671537)~~

摘　　要：为比较禽类恒定链的结构和功能,应用RACE(Rapid Amplification of cDNA Ends)技术首次克隆并鉴定了鸽恒定链基因。首先用一对含高度保守的DNA片段的简并引物,从鸽脾细胞RNA扩增部分恒定链片段,接着测序并设计新引物分别从5′和3′RACE扩增延长该片段。最后根据全基因的序列设计上、下游引物,获得大小为1050bp的全长cDNA。比较核苷酸序列,鸽与鸡的Ii链同源性达到82.8%,而与人等其它动物的同源性则在52.0%以上;其中633bp的开放阅读框编码211个氨基酸残基的前体蛋白。推导和分析氨基酸序列表明,分子结构与鸡恒定链相似,其中有些氨基酸残基表现出较高的保守性。In order to compare the smlcture and function of pigeon invariant chain （pIi） gene with other avian＇s, pIi gene was cloned using a method of RACE （Rapid Amplification of eDNA Ends）. Firstly, according to high conservative nucleotide sequence of homologous fragment in avian invariant chain （Ii） gene, a pair of degenerated primer was designed, and a special DNA fragment was gained from pigeon spleen cell RNA by PCR. Then based on the sequence of gained DNA fragment, some new primers were designed, and the 3 ＇ terminal and the 5 ＇ terminal of pli gene were cloned by RACE re- spectively. Finally a complete eDNA of pli was to extend with newly designed primer by PCR. The product was identified by electrophresis and sequence analysis. The results of sequencing indicate that pli gene is 1 050 bp in length （GenBank No. AY904337）, which includes an open reading frame of 633 bp encoding a precursor protein with 211 amino acid residues. In comparison with the nucleotide sequences of other species＇ Ii genes, pli is similar to chicken＇s, showing an overall identity of 82.8% with chicken and over 52.0% with human and other mammalian animals. In addition, some amino acid residues in Ii molecule manifest extremely conservative among animals, which suggests that they could have an important biological function.

关 键 词：鸽 恒定链 RACE 克隆 

分 类 号：Q78[生物学—分子生物学] TP392[自动化与计算机技术—计算机应用技术]