我国间日疟原虫地理株SSUrDNA特定序列的比较分析

用已设计的一对特异引物和建立的双温度点聚合酶链式反应（ＰＣＲ）技术，分别从我国安徽、福建、海南、四川及云南五省疟区采集的间日疟患者血样ＤＮＡ抽提物中，扩增出长约６４０个碱基对（ｂｐ）的ＤＮＡ片段，经限制性酶切鉴定，证实为间日疟原虫小亚单位核糖体核糖核酸基因（ＳＳＵｒＤＮＡ）目的片段。将其分别与载体Ｍ１３ｍｐ１８和Ｍ１３ｍｐ１９连接、克隆，以双脱氧末端终止法测序，并分析比较。结果表明，同一地区二份样本序列完全相同，国内间日疟原虫地理株间及其与已报道的国外虫株克隆间，该序列显示出高度的同源性，但亦存在由个别碱基置换，插入或缺失所表现出的差异。

COMPARISON AND ANALYSIS OF SEQUENCES OF SSUrDNA FRAGMENTS AMPLIFED FROM DIFFERENT GEOGRAPHICAL ISOLATES OF PLASMODIUM VIVAX OF CHINA

With two specific primers designed and two temperature point polymerase chain reaction established successfully, the desired small subunit ribososmal DNA fragment of plasmodium vivax was amplified from genomic DNA extracted respectively from blood samples of P. vivax malaria patients collected in Anhui, Fujian, Hainan, Sichuan and Yunnan provinces of China(two cases/each province). The amplified DNA fragments were identified by digestion of restriction endonucleases and ligated to vector(M13mp18 and M 13mp19) and cloned. The sequences of amplified fragments were determined with dideoxynucleotide terminatior method and further compared each other.It was showed that the sequences of two samples of vivax malaria pateints from same regions were completely constant and there were high homology amongst the sequences of SSUrDNA fragment of Plasmodium vivax isolates from different regions with very few point mutation resulting from nucleotide substitution and deletion or insertion which brought about the change of some restriction endonucleases sites.