中文摘要：

目的 分析我国云南中缅边境等地5种疟原虫18S rDNA的基因差异和种系发育。 方法 2000-2015年收集来自我国云南中缅边境等地的疟疾患者血样（或疟原虫DNA），提取血样中的疟原虫DNA，对它们的18S rDNA基因进行扩增、测序分析，并与GenBank中疟原虫相应序列进行比较分析，利用邻接法（neighbor joining, NJ）、最大似然法（maximum likelihood, ML）和最大简约法（maximum parsimony, MP）构建系统进化树。 结果 共收集了94例疟疾患者血样或DNA，所有样品均扩增出18S rDNA基因序列。序列比对分析显示，恶性疟原虫（Plasmodium falciparum）、间日疟原虫（P. vivax）、三日疟原虫（P. malariae）、卵形疟原虫（P. ovale）和诺氏疟原虫（P. knowlesi）的种内差异分别为0～0.2%、0～0.1%、0～0.1%、0～0.1%和0。种系发育关系分析显示，NJ、MP和ML法构建的系统进化树的拓扑结构基本一致。本研究的疟原虫形成5个大的分支：恶性疟原虫形成一个分支，与GenBank中来自喀麦隆（KC428741、KC428742）、巴西（KC906718）和马来西亚（HQ283221）的分离株聚集在一起；间日疟原虫形成一个分支，其中大部分样品与来自喀麦隆（HF945443）、印度（HM014361、JQ627158）和哥伦比亚（U83877）的分离株形成一较小分支，小部分样本（Pv11、Pv18和Pv21）形成一个更小的分支后与食蟹猴疟原虫（P. cynomolgi）（L07559）相聚形成一较小分支；三日疟原虫形成一个分支，来自云南的三日疟原虫Pm1、Pm3和Pm4聚在一个小分支内，并与来自日本的分离株（AB250682）相聚，再与来自海南的分离株Pm5相聚，显示出地区差异性；卵形疟原虫形成一个分支，与来自越南的分离株（EU935736、AF387038）聚在一起；诺氏疟原虫形成一个分支，与来自缅甸的分离株（GU816250、GU816246）聚在一起。 结论 我国云南中缅边境等地5种疟原虫18S rDNA基因均无明?

英文摘要：

Objective To analyze sequence variation and construct phylogenetic tree based on 18S ribosomal DNA among five species of Plasmodium in Yunnan border between China and Myanmar and other areas. Methods Blood samples（or DNA samples）from malaria patients were collected from 2000 to 2015 in Yunnan border and Myanmar and other areas. DNA was extracted from blood samples, and the 18S rDNA fragment was amplified, sequenced and aligned with relevant sequences available in the GenBank. The phylogenetic tree was constructed by methods of neighbor joining（NJ）, maximum likelihood（ML）, and maximum parsimony（MP）, respectively. Results A total of 94 blood samples or DNA from malaria patients were collected. The 18S rDNA was successfully amplified from all the samples. Sequence alignment revealed variations of 0-0.2%, 0-0.1%, 0-0.1%, 0-0.1% and 0 for 18S rDNA sequence among Plasmodium falciparum, P. vivax, P. malariae, P. ovale and P. knowlesi, respectively. The phylogenetic tree constructed with the three method showed consistency. Phylogenic analysis revealed that there were five big branches of Plasmodium spp. studied. The P. falciparum branch clustered with the isolates from Cameroon（KC428741, KC428742）, Brazil（KC906718）, and Malaysia（HQ283221） in GenBank. The P. vivax branch clustered with isolates from Cameroon（HF945443）, India （HM014361, JQ627158）, and Colombia （U83877）. However, the samples Pv11, Pv18 and Pv21 formed a small branch that showed closer phylogenetic relationship with P. cynomolgi（L07559）, an isolate from Macaca fascicularis. Moreover, P. malariae samples from Yunnan Province including Pm1, Pm3 and Pm4 clustered to form a small branch, and then clustered with samples from Hainan Province, showing geographical diversity. All the isolates of P. ovale clustered with isolates from Vietnam（EU935736 and AF387038）. All the isolates of P. knowlesi clustered into a branch, and showed close relationship with those from Myanmar（GU816250 and GU816246）. Conclusion There