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目的 :为了确定湖北省间日疟原虫虫株环子孢子蛋白 ( CSP)的分型和探讨 CSP多态性的生物学特征。方法 :采用常规的克隆和 Sanger链终止法 ,首次对湖北省间日疟原虫的环子孢子蛋白 ( CSP)基因测序。结果 :HB2株 CSP基因的 N- C-端非重复区包括重复区后可变区核苷酸序列与北朝鲜 ( NK)株和中国株 ( CH2 - CH7)相同 ,而中央前后重复区则有较大变异。在 HB2 CSP中央前后重复区 ,有 8种变异型。与其它已发表的间日疟原虫 CSP核苷酸序列相比 ,重复体 GNGAG-GQP/AA和重复后可变区有明显的地理学特征。此外同一份 HB2 CSP基因 PCR产物克隆后获得含两个大小不等插入片段的阳性克隆 ,分别为 0 .75kb和 1.1kb。两者非重复区的核苷酸序列相同 ,在中央前后重复区除了重复数次不同外 ,仅有 3处隐性核苷酸变异和 1处显性核苷酸变异。结论 :CSP基因变异 ,尤其是重复区的变异不仅与 DNA聚合酶的自身作用有关 ,而且还可能牵涉到间日疟原虫潜伏期的改变。
Objective: To determine the typing of circumsporozoite sporozoite protein (CSP) in Plasmodium vivax in Hubei Province and to explore the biological characteristics of CSP polymorphism. Methods: The circumsporozoite protein (CSP) gene of Plasmodium vivax was sequenced in Hubei province for the first time by routine cloning and Sanger chain termination method. Results: The N-C-terminal non-repetitive region of CSP gene of HB2 strain contained the same variable region nucleotide sequence as that of North Korea (NK) strain and Chinese strain (CH2 - CH7), while the central repeat region had Big variation. In the HB2 CSP central repetition zone, there are 8 kinds of variants. Repeats GNGAG-GQP / AA and post-repetitive variable regions have distinct geographical features compared to other published CSP nucleotide sequences of Plasmodium vivax. In addition, the same HB2 CSP gene PCR product was cloned and two positive clones with two fragments of different sizes were obtained, which were respectively0.75kb and1.1kb. The nucleotide sequences of the two non-repetitive regions were the same. There were only three recessive nucleotide variations and one dominant nucleotide mutation in the central repeat before and after addition of several repetitions. Conclusion: The variation of CSP gene mutation, especially the duplication region, is not only related to the DNA polymerase’s own role but also may involve the change of incubation period of Plasmodium vivax.