恶性疟原虫云南株环子孢子蛋白部分基因的克隆和序列分析

目的：测定我国恶性疟原虫环子孢子蛋白部分基因序列，了解我国虫株与其它虫株CS蛋白基因序列的差异。方法：采用PCR方法特异性扩增CS蛋白基因片段，并将该基因片段克隆于M13噬菌体，取3个阳性克隆制备M13－CSP单链DNA，用双脱氧链末端终止法测定该基因片段核苷酸序列。应用PCGENE软件对六个虫株CS蛋白基因序列进行了一系列比较分析。结果：我国恶性疟原虫云南株（PFD－3／YN）与T4、Welcome、NF54、3D7及7G8等虫株CS蛋白基因序列有不同程度的差异，其中一个有意义核苷酸突变发生在P．fTh／Tc抗原表位区。结论：云南株与其它虫株CS蛋白基因存在差异。

CLONING AND SEQUENCE ANALYSIS OF THE GENE ENCODING THE PARTIAL REGION CS PROTEIN OF A PLASMODIUM FALCIPARUM ISOLATE FROM YUNNAN

AIM:Determining nucleotide sequence of the circumsporozoite protein partial gene of the Plasmodium falciparum PFD-3/YN(Yunnan of China)and finding out the differences of the CS gene sequence between Chinese Plasmodium falciparum isolate and other isolates.METHODS:The circumsporozoite protein gene fragment was amplified by polymerase chain reaction and cloned into M13 bacteriophage.M13 CSP single strand DNAs of the three positive clones were extracted respectively.Then,the nucleotide sequence of the CS gene ragment was determined by the dideoxy chain termination method. PCGENE software was used to compare and analyze the CS gene sequence of the six isolates.RESULTS:Different degrees of diversity of the CS gene sequences were found among P.falciparum PFD-3/YN and other isolates(T 4,Wellcome,NF54,3D7 and 7G8).A non silent substitution at the nucleotide level being found in the P.f Th/Tc antigenic epitope region.CONCLUSION:There were differences in the CS gene sequence among P.falciparum PFD-3/YN and those of other isolates.