摘要
目的研究不同地理分离株恶性疟原虫裂殖子顶端膜抗原1(Pf AMA-1)基因的多态性。方法采集2006-2012年福建省23例输入性恶性疟患者的血样,以血样中的疟原虫DNA为模板,巢式PCR扩增AMA-1基因片段,利用生物软件进行序列比对分析。结果 23份血样均扩增出目的条带(约505 bp),发现32个多态位点,共计18个单倍型,其中8个为新报道序列。来自非洲的恶性疟原虫分离株的AMA-1基因序列具有较丰富的遗传多样性[单倍型多样度(Hd)=0.985,核苷酸多样度(π)=0.0258],亚洲(东南亚和中国云南)的遗传多样性相对较低(Hd=0.909,π=0.0221)。多样化选择分析结果显示,非同义突变率与同义突变率差值(d N-d S)为0.031±0.006,中性检验结果均无统计学意义(P>0.05)。基因内重组分析显示,重组事件的最低数量(Rm)为10,连锁不平衡指数R2随核苷酸遗传距离增加呈明显下降趋势。采用邻接法构建的分子系统树显示,所有分离株分为3个群(G1,G2和G3),G1多为非洲分离株,G3大部分为亚洲分离株。结论来自非洲的恶性疟原虫分离株的AMA-1基因序列具有较丰富的遗传多样性。
Objective To study the genetic diversity of apical membrane antigen-1 gene from Plasmodium falciparum （PfAMA-1）. Methods Filter paper blood samples were collected from 23 imported P. falciparum malaria patients who returned to Fujian Province from 2006 to 2012. Nested PCR were used to amplify the PfAMA-1 gene. The amplified fragments were sequenced, and analyzed by bioinformatic software. Results All 23 samples were amplified a 505 bp band. Thirty-two nucleotides were found to be variable, resulting in 18 haplotypes. Eight of these 18 halotypes were being reported here for the first time. The parasites collected from Africa showed the higher level of variability [haplotypes diversity （Hd）= 0.0985, nucleotide diversity （π）=0.0258] as compared to the isolates from Asia （Hd=0.909, π=0.0221）. The average difference of dN-dS for all 23 PfAMA-1 sequences was 0.031±0.006. Sequence-based neutrality tests were not significant in Africa and Asia （P〉0.05）. The minimum number of recombination events （Rm） was 10, and the linkage disequilibrium index （R2） evidently declined with the increase of nueleotide distance. A molecular phylogenetic tree constructed using the neighbor-joining method showed that the 23 isolates were assigned to three clades （G1, G2 and G3）. Most samples from Africa formed G1, and G3 contained most of Asian isolates. Conclusion Plasmoclium falciparum isolates from Africa show a higher genetic diversity than the isolates from Asia for PfAMA-1 gene.
出处
《中国寄生虫学与寄生虫病杂志》
CAS
CSCD
北大核心
2014年第5期344-347,共4页
Chinese Journal of Parasitology and Parasitic Diseases
基金
福建省自然科学基金(No.Z0516066)~~
关键词
恶性疟原虫
顶端膜抗原1
基因多态性
Plasrnodium falciparum
Apical membrane antigen 1
Genetic polymorphism
