药用寄生植物锁阳线粒体基因内含子序列分析  

Mitochondrial Gene Intron Sequences Analysis of Medicinal Parasitic Plant Cynomorium songaricum

作　　者：苏小娟[1,2] 刘广达[1,2] 刘英[1,2] 冯晓宇[1,2] 陈贵林[1,2] 

机构地区：[1]内蒙古大学生命科学学院,呼和浩特010021 [2]内蒙古自治区中蒙药材规范化生产工程技术研究中心,呼和浩特010021

出　　处：《基因组学与应用生物学》2015年第2期373-381,共9页Genomics and Applied Biology

基　　金：国家自然科学基金(31260117);国家科技支撑计划课题(2011BAI07B07)共同资助

摘　　要：被子植物线粒体cox1基因的Group玉内含子常含有水平基因转移(horizontal gene transfer,HGT)现象。本研究对药用寄生植物锁阳(Cynomorium songaricum)线粒体基因cox1、cox2、nad1序列进行扩增分析,利用最大似然法对cox1和cox2基因内含子和外显子分别进行聚类分析,结果显示cox1内含子聚类结果与其他3个聚类结果不相符,说明该内含子可能存在水平基因转移现象。对比了锁阳6个不同居群间线粒体基因cox1、cox2、nad1外显子与内含子序列平均距离,发现6个不同居群间cox1基因内含子同源性高达100%,说明该基因内含子可能具有功能。结合生物信息学分析表明该内含子很有可能编码核酸内切酶,而DNA核酸内切酶被认为能促进内含子的转移。3'Co-conversion tracts(3'CCT)是被子植物内含子发生转移的痕迹,对锁阳cox1基因序列进行检测发现其含有3'CCT序列且长度为35 bp,RT-PCR实验验证得到cox1基因内含子可以独立转录m RNA。因此,锁阳cox1基因内含子很可能编码一个核酸内切酶,且促进了其内含子的转移。Cox1 gene group玉introns in angiosperm always have the phenomenon of horizontal gene transfer（HGT）. We have amplified and analyzed the sequences of mitochondrial cox1, cox2 and nad1 genes in medicinal parasitic plant Cynomorium songaricum. By using the maximum likelihood method to analyze the phylogeny of cox1, cox2 gene intron and exon, we found that the phylogeny of cox1 gene intron results did not match another three, which suggested the intron may have HGT phenomenon. We compared the average distances of exon and intron sequences of mitochondrial cox1, cox2 and nad1 gene in six different populations of C. songaricum, and found that among six different populations cox1 intron homology up to 100%. The result suggested the intron of cox1 gene may have function. Bioinformatics analysis showed that the intron most likely codes endonuclease,while the DNA endonuclease is thought to promote the intron to transfer. 3＇Co-conversion tracts（3＇CCT） is angiosperm intron traces metastasis 3＇CCT analysis testing showed C. songaricum contain it and a length of 35 bp.RT-PCR indicated cox1 intron can be transcribed to mRNA independently. So, C. songaricum cox1 gene intron most likely codes endonuclease, which can promote the intron to transfer.

关 键 词：线粒体基因 内含子 水平基因转移 序列分析 锁阳 

分 类 号：Q943.2[生物学—植物学]