基于18S rRNA基因测序基础上的锥虫分子分类学  

Phylogenetic relation of Trypanosome based on 18S rRNA gene sequencing

作　　者：刘光远[1] 田占成[1] 龚真莉[1] 谢俊仁[1] 李知新[1] 

机构地区：[1]中国农业科学院兰州兽医研究所家畜疫病病原生物学国家重点实验室甘肃省动物寄生虫病重点实验室,甘肃兰州730046

出　　处：《中国兽医学报》2009年第9期1140-1143,共4页Chinese Journal of Veterinary Science

基　　金：国家科技基础条件平台资助项目(2005DKA21205-3);国家高新技术研究发展计划"863"资助项目(2006AA10A207);甘肃省自然科学基金资助项目(32S041-A25-035)

摘　　要：利用18S rRNA基因序列分析方法，对我国湖北、广西、新疆和浙江4省的伊氏锥虫及1株布氏锥虫进行分子分类学研究。用分离的锥虫感染实验动物，自感染小鼠的红细胞或全血中提取基因组DNA，根据GenBank中已发表的锥虫18S rRNA序列设计1对锥虫通用引物，通过PCR扩增目的基因片段，将扩增产物连接到pGEM—T载体中，经酶切、PCR确定．进行序列测定。结果显示，7个锥虫分离株的18S rRNA基因大小为2188bp。利用DNAStar对试验所获得的这7株堆虫和GenBank中部分锥虫的18S rRNA基因进行比较分析，建立2个进化系统发生树。核苷酸同源性比较及系统发生树显示：自我国上述4省分离的伊氏锥虫来源于同一株系，布氏锥虫和广西分离的伊氏锥虫株的18S rRNA核苷酸与其他锥虫分离株仅有较小差异，与国外的6株锥虫的同源性为99％～100％。与另外7株的同源性为62％。The phylogenetic relation of Trypanosoma sp in Hubei, Guangxi, Xinjiang, Zhejiang provinces and a strain of Trypapnosoma bruce were analyzed by using 18S rRNA sequence. The genome DNA was extracted from the red blood cells or blood of the infected mouse which include as isolates of Trypanosoma from these different geo- graphic areas. The gene specific primers were designed according to the pubulished 18S rRNA sequence at Gengank. The target DNA segment was amplified by polymerase chain reaction, the PCR product was ligated into pGEM-T easy vector. It was identified by PCR and sequencing. The results suggested that the length of 18S rRNA gene seven Trypanosoma sp involved in this study was around 2 188 bp. Two phylogenetic trees was inferred based on 18S rRNA sequence of six Trypanosoma evansi strains in Hubei, Xinjiang, Zhejiang, Guangxi provinces, a Trypanosoma bruce strain and the other species of Trypanosoma available in GenBank. In the first tree,it was analyzed that the homologies of seven Trypanosoma strains were 99.8%, 100%, respectively. The homology between them and 6 of 13 foreign Trypanosoma were 99 %-100 %,62 % between them and 7 foreign Trypanosome strains.

关 键 词：锥虫 18S RRNA基因 分子分类学 

分 类 号：S852.72[农业科学—基础兽医学]