ALLELIC DIMORPHISM IN A SURFACE-ANTIGEN GENE OF THE MALARIA PARASITE PLASMODIUM-FALCIPARUM
ALLELIC DIMORPHISM IN A SURFACE-ANTIGEN GENE OF THE MALARIA PARASITE PLASMODIUM-FALCIPARUM
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DOI：
10.1016/0022-2836(87)90649-8
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发表时间：
1987-05-20
影响因子：
5.6
通讯作者：
SCAIFE, JG
中科院分区：
文献类型：
--
作者：
TANABE, K;MACKAY, M;SCAIFE, JG
恶性疟原虫的裂殖子携带由称为p190或p195的前体加工而成的表面蛋白。在这种蛋白质中已经报道了多态性。由于该蛋白是疟疾疫苗的候选蛋白，因此了解这种多态性的性质是重要的。我们已经确定了完整的核苷酸序列的p190基因的MAD 20株（巴布亚新几内亚分离）。将该基因与其它恶性疟原虫株的基因进行比较，研究了该抗原多态性的遗传基础。该基因由分布在可变区中的序列组成，这些可变区被保守或半保守序列分开。可变序列出现在编码三肽重复序列的区域和没有明显重复序列的区域。有趣的是，根据目前的数据，可变序列不是广泛多态的，而是分为两种不同的类型。我们认为，p190蛋白编码的二态等位基因能够有限的遗传交换和目前的证据在核苷酸水平上记录疟原虫基因内重组。
Merozoites of the malaria parasite Plasmodium falciparum carry surface proteins processed from a precursor termed p190 or p195. Polymorphism has been reported in this protein. Since the protein is a candidate for malaria vaccine, it is important to understand the nature of this polymorphism. We have determined the complete nucleotide sequence of the p190 gene from the MAD20 strain (a Papua New Guinea isolate). Comparisons of the gene with that from other strains of P. falciparum allowed us to study the genetic basis of the antigen''s polymorphism. The gene consists of sequences distributed in variable blocks, which are separated by conserved or semi-conserved sequences. Variable sequences occur both in regions that code for tripeptide repeats and in regions with no apparent repeats. Interestingly, according to the present data, variable sequences are not widely polymorphic but fall into two distinct types. We argue that the p190 proteins encoded by dimorphic alleles capable of limited genetic exchange and present evidence at the nucleotide level documenting intragenic recombination in Plasmodium.