Cloning and Sequence Analysis of Three Plant Ran Genes

3种植物Ran基因的克隆及序列分析(摘要)(英文)

[Objective]The aim was to study homology between Ran gene in Allium cepa,Allium sativum and Brassica napus and Ran2 gene in Arabidopsis in order to determine whether three kinds of plant material as substitute for Arabidopsis. [Method]By using RT-PCR method,homology gene was cloned from totoal RNA which extracted from splinter cells of Allium cepa,Allium sativum and Brassica napus with Arabidopsis Ran2 primer,then,carrying out sequence and comparative analysis. [Result]The results showed that the open reading frames of Ran genes in Allium cepa,Allium sativum and Brassica napus were 666,663,666 bp,coding 221,220 and 221 amino acids respectively,with the molecular weight of 24.3 kDa. The sequence analysis showed that the amino acid homology of Ran genes between Allium cepa,Allium sativum,Brassica napus and Arabidopsis Ran2 were respectively 99.1 %,100 % （except an Asp D at Allium sativum C terminal）,96.4 %. The phylogenetic tree indicated that Ran genes from Allium cepa and Allium sativum had closer evolutionary relationship with Arabidopsis Ran2. [Conclusion]The research laid a foundation for further study on the biological function of plant Ran gene.

[目的]研究洋葱、大蒜和油菜中Ran基因与拟南芥Ran2基因的同源性,以确定3种植物材料能否作为拟南芥的替代材料研究Ran定位。[方法]采用RT-PCR方法,以拟南芥Ran2的引物分别从洋葱、大蒜和油菜分裂细胞提取的总RNA中扩增出相应片段DNA(AcRan,AsRan,BnRan),经凝胶电泳回收相应PCR产物,克隆到pMD18-T载体上,转化到DH5α中,抽提质粒,经酶切、PCR鉴定确定阳性克隆,将阳性克隆的菌体进行测序、比对分析。[结果]洋葱、大蒜和油菜的Ran基因开放阅读框分别为666、663和666bp;分别编码221、220和221个氨基酸,分子量约24.3kD;与拟南芥AtRan2氨基酸序列同源性分别为99.1%、100%(除末端缺少1个天冬氨酸D外)和96.4%;进化树分析显示洋葱和大蒜Ran基因与拟南芥进化关系更近,其根尖可代替拟南芥根尖研究Ran基因的定位或相关生物学功能。将该实验克隆的3种植物Ran基因序列与收集的14种植物的Ran序列共28种进行氨基酸同源性比对及进化树分析表明,高等植物Ran基因绝大多数在进化树中处于同一位置,同源性高达90%以上(拟南芥AtRan4和水稻OsRan4例外),因此,它们可能在植物细胞分裂过程中起着相似的作用;且3种植物在受动结合域(EBD)和酸性末端(AT)存在不同;而拟南芥AtRan4缺少这2个功能域,可能与AtRan1～3具有不同的作用。[结论]为进一步研究植物Ran基因的生物学功能奠定了基础。