Relative frequencies of polymorphisms of variation in Block 2 repeats and 5′ recombinant types of Plasmodium falciparum msp1 alleles
Relative frequencies of polymorphisms of variation in Block 2 repeats and 5′ recombinant types of Plasmodium falciparum msp1 alleles
复制标题
DOI：
10.1016/j.parint.2003.11.002
复制
发表时间：
2004-03-01
影响因子：
1.9
通讯作者：
Tanabe, K
中科院分区：
文献类型：
--
作者：
Sakihama, N;Matsuo, T;Tanabe, K
恶性疟原虫裂殖子表面抗原 1 基因座 (pfmsp1) 产生遗传多态性的机制包括不同类型的二态性 Block 2 9 核苷酸重复单元的插入和删除以及基因内重组。为了研究这两种不同机制的相对发生频率，我们开发了一种灵敏的 PCR 策略来识别同一样本中的 5' 重组类型和 Block 2 重复次数。该方法可以以 1-4 个 pfmsp1 拷贝的灵敏度特异性检测目标 5' 重组类型（块 2-6）。将新方法应用于所罗门群岛的现场分离株，使我们能够鉴定出六种不同的 5' 重组类型以及其中三个的 Block 2 重复数变异，从而区分 10 个不同的等位基因。这些等位基因在研究区域当地三个村庄的分布表明，Block 2 9-bp 重复次数的变异频率和 Block 2-6 内的重组事件是相互独立的，并且与所罗门群岛恶性疟原虫群体中 pfmsp1 位点的重组事件相比，重复变异的频率相对较高。 (C) 2004 Elsevier Ireland Ltd. 保留所有权利。
The mechanisms producing the genetic polymorphism at Plasmodium falciparum merozoite surface antigen-1 locus (pfmsp1) include the insertion and deletion of the different type of dimorphic Block 2 9-nucleotide repeat units as well as the intragenic recombination. To study relative occurrence frequencies of these two distinct mechanisms, we have developed a sensitive PCR strategy to identify both 5' recombinant types and the number of Block 2 repeats from the same sample. This method can specifically detect the target 5' recombinant type (Blocks 2-6) at the sensitivity of 1-4 copies of the pfmsp1. Applying the new method to field isolates from the Solomon Islands enabled us to identify six different 5' recombinant types and variation in Block 2 repeat number in three of them, thus distinguishing 10 different alleles. Distribution of these alleles in local three villages in the study area suggests that frequencies of variation in the number of Block 2 9-bp repeats and recombination events within Blocks 2-6 are mutually independent and the frequency of repeat variation is relatively high as compared to that of recombination events at the pfmsp1 locus in P falciparum populations from the Solomon Islands. (C) 2004 Elsevier Ireland Ltd. All rights reserved.