青海省细粒棘球蚴线粒体cox1基因和nad1基因多态性的研究

Nucleotide polymorphism of cox1 and nad1 genes of Echinococcus granulosus metacestode isolates collected from Qinghai Province

分析了采自青海省7个县共19个细粒棘球蚴分离株样品的nad1基因和cox1基因核苷酸序列的多态性和单倍型。结果显示,18个细粒棘球蚴分离株属于G1型,1个分离株属于G3型。G1型分离株可根据nad1基因和cox1基因的核苷酸序列变异分为不同的单倍型,其中nad1基因的单倍型共有5种,变异位点只有5个,单倍型序列之间碱基差异1~4个,变异率达0.45%;而cox1基因的单倍型共有9种,涉及变异位点共27个,单倍型序列之间碱基差异1~11个,变异率达0.68%。突变碱基多位于密码子第3位碱基上,属于同义突变。cox1基因的多态性比nad1基因的多态性丰富。用于细粒棘球蚴G1型内分离株之间核苷酸多态性的分析则分辨率相对较高。上述研究结果为进一步开展棘球蚴病分子流行病学调查积累了数据。

This study was to analyze nucleotide polymorphisms and haplotypes of complete mitochondrial nad1 and cox1genes of 19 isolates of Echinococcus granulosus metacestodes collected in seven counties of Qinghai Province.In result,18 of the isolates belonged to G1 genotype,and one to G3.Of the G1 isolates,5haplotypes occurred in the nad1 gene with 5nucleotide mutation sites and 1to 4nucleotide differences or the highest variation rate of 0.45%,whereas 9haplotypes existed with 27 nucleotide mutation sites and 1to 11 nucleotide differences or the highest variation rate of 0.68%for the cox1 gene.Most mutations appeared in the third base of a codon,which hardly leads to the change of their encoded amino acids.Single nucleotide polymorphisms for cox1 gene were more than those for the nad1 gene,suggesting that the resolution ratio of the cox1 gene should be relatively higher than that of the nad1 gene in analysis of the nucleotide polymorphisms within E.granulosus G1 isolates.In conclusion,the above-mentioned results provide important data for further molecular epidemiological investigation of echinococcosis.