鸡球虫18S rRNA基因序列的测定与分析  

Sequence and Phylogenetic Analysis of 18S rRNA Gene for Eimeria in Chicken

作　　者：王鑫[1,2] 韩红玉[1] 姜连连[1] 赵其平[1] 董辉[1] 韩静芳[1] 黄兵[1] 

机构地区：[1]中国农业科学院上海兽医研究所农业部动物寄生虫学重点开放实验室,上海200241 [2]聊城大学材料科学与工程学院,聊城252059

出　　处：《生物技术通报》2009年第S1期305-309,共5页Biotechnology Bulletin

基　　金：国家科技基础条件平台建设作项目(2005DKA21205-4)

摘　　要：为了利用18S rRNA基因进行鸡球虫系统进化分析,对巨型艾美耳球虫(Eimeria maxima)、柔嫩艾美耳球虫(E. tenella)、堆形艾美耳球虫(E.acervulina)3种共8个不同来源的虫株,分别提取总DNA进行18S rRNA基因的扩增和测序;将得到的序列登录GenBank进行同源性和趋异性分析,并结合GenBank中其它原虫的18S rRNA基因序列构建进化树。结果显示扩增获得8株鸡球虫18S rRNA基因长度为1 746～1 756 bp,序列比对显示同种不同株间的同源性大于不同种间的同源性,其中3株E.maxima株间同源性在98.7%～99.3%之间,4株E.tenella株间同源性在99.7%～99.9%之间;不同种间同源性为96.5%～98.1%,其中E.maxima与E.tenella的遗传距离最大,为0.038;E.maxima与E.acervulina的遗传距离最小,为0.021。顶复器门9个不同属所构建的进化树结果显示,E.imeria和等孢属(Isospora)聚为一支,说明亲缘关系比较近。与GenBank中其它5株不同鸡球虫的18S rRNA基因共同构建的进化树显示,3株E.maxima聚为一支,与E.brunetti、E.mitis、E.mivati、E.praecox和E. acervulina聚为一大分支;4株E.tenella与1株E.necatrix共同形成一个分支,说明E.tenella与E.necatrix的亲缘关系最近。本研究证实了在鸡球虫系统进化研究中,18S rRNA基因不仅可以区分不同种,而且有可能成为区分同种不同株的理想靶基因。To analysis the sequences and relationship of 18S rRNA gene of Eimeria in chicken,the genomic DNA of 8 strains of Eimeria were extracted.The 18s rRNA genes were amplified by PCR respectively.The results of the sequencing show that the 18s rRNA fragments were between 1 746 bp to 1 756 bp.Compared of all sequences indicated there were some differences among the 8 strains.The discrepancy was greater between species than strains.The similarity was 98.7%～99.3%in 3 strains of E.maxima and 99.7%～99.9%in 4 strains of E.tenella,then the similarity was 96.5%～98.1%.between 3 species of Eimeria.The generic distance of 18s rRNA genes from 8 strains of Eimeria revealed that the farthest distance was 0.038 between E.maxima and E.tenella,the nearest was 0.021 between E.maxima and E.acervulina.The phylogenetic tree showed that Eimeria was closed to Isospora,and 3 strains of E. maxima were closed to each other,and so did the 4 strains of E.tenella.E.tenella was close to E.necatrix,and the variability with E. acervulina,E.mivati,E.mitis,E.praecox and E.brunetti was obvious.These results proved that the 18s rRNA gene could be an ideal DNA molecular to identify different species and strains of Eimeria.

关 键 词：鸡 球虫 艾美耳球虫 18S RRNA 序列分析 系统进化 

分 类 号：S852.7[农业科学—基础兽医学]