用聚合酶链反应技术鉴别恶性疟原虫不同地理株的初步研究

IDENTIFICATION ON DIFFERENT GEOGRAPHIC STRAINS OF PLASMODIUM FALCIPARUM BY USING PCR

目的 阐明 Fcc1/ HN株与云南株间的不同生物学特性。 方法 用 M2 6 - 32 作探针 ,筛选恶性疟原虫 c DNA基因表达文库 ,根据所获得的靶抗原决定簇表位的基因序列设计引物 ,分别进行 PCR扩增 ;地高辛酶促生物标记 Fcc1- HN株 DNA的 PCR扩增产物 ,分别与 Fcc1/ HN株 DNA、云南株 DNA和阳性克隆 5 11的扩增产物杂交。 结果 PCR扩增后 Fcc1/ HN株 DNA在约 5 0 0 bp和 4 5 0 bp处有 2条特异性条带 ;云南株 DNA在约 5 0 0 bp处有 1条较淡的条带和 130 0bp处一较亮的特异性条带 ;阳性克隆 5 11仅在约 5 0 0 bp处有 1条特异性条带。标记探针能与克隆 DNA、恶性疟原虫Fcc1/ HN株和云南株的 PCR扩增产物杂交。 结论 恶性疟原虫 Fcc1/ HN株与云南株在基因组 DNA结构上可能存在差异。

Objective To identify the biological characteristics of Plasmodium falciparum(P.f ) Fcc1/HN strain and P.f Yunnan strain. Methods One pair of primer for amplification of P.f. by PCR was designed based on the sequence of a new gene which screened from the cDNA library of P. falciparum by a specific DNA probe containing the NKND sequence and the epotopes of pan species monoclonal antibody M26 32. The PCR products from amplified DNA of Fcc1 HN strain labeled with digoxigenin was hybridized with DNA of Fcc1/HN strain, Yunnan strain, and amplified DNA products from positive 511 clone. Results Two specific bands, 500 bp and 450 bp, presented in the amplified DNA of Fcc1/HN by PCR, and another two bands, 500 bp and 1 300 bp, appeared in the that of Yunnan strain, and only one specific band, 500 bp, presented in the positive 511 clone. The labeled probe can hybridized with the PCR amplified products of cloned DNA, P.f Fcc1/HN strain and Yunnan strain. Conclusion Differences appeared in the genome DNA structure of P.f. Fcc1/HN and Yunnan strain.