中国日本血吸虫地域株基因差异的研究

目的　研究中国日本血吸虫各地域株基因差异。　方法　收集湖南、安徽、湖北、四川及江苏 5省的阳性钉螺 ,将逸出的日本血吸虫尾蚴感染昆明小鼠 ,42d后 ,用灌注法获取成虫 ,用PCR扩增成虫线粒体NADH (还原型烟酰胺腺嘌呤二核苷酸 )脱氢酶 1(ND1)和细胞色素C氧化酶 1(CO1)基因片段 ,克隆于质粒载体后测序并用MEGA软件分析。　结果　各地域株日本血吸虫成虫的ND1和CO1基因长度分别为 476bp和 10 33bp ,ND1和CO1基因序列分别存在 2个单倍体 (Ⅰ型 ,Ⅱ型 ) ,其差异分别为 4.0 %和 3.4%。从分子发生树看 ,各地域株日本血吸虫ND1和CO1基因分别存在 2个不同基因型。在ND1基因中呈现Ⅰ型的 ,CO1基因中也为Ⅰ型 ,反之 ,均为Ⅱ型。　结论　研究区域湖南、安徽、湖北、四川及江苏 5省的日本血吸虫株ND1和CO1基因存在 2个不同基因型。

Study on Genomic Diversity among Different Isolates of Schistosoma japonicum in China

OBJECTIVE: To study genomic diversity among the isolates of Schistosoma japonicum in China. METHODS: Schistosome adults were collected from different endemic areas. Mitochondrial NADH dehydrogenase 1 (ND1) and cytochrome C oxidase 1 (CO1) gene fragments of the worms were amplified by PCR, cloned into plasmid, and finally sequenced. Program MEGA was used for sequence analysis. RESULTS: The ND1 and CO1 genes amplified from different geographic strains were 476 bp and 1,033 bp, respectively. There are two distinct haplotypes, type I and II, for both ND1 and CO1 nucleotide sequences. The differences between the two types were 4.0% and 3.4%. They are considered to be two different genetypes by the phylogenetic analysis. In individual mitochondrial gene, type I of ND1 was fixedly accompanied with type I of CO1 gene, and type II of ND1 with type II of CO1. CONCLUSION: There are two different genetypes of ND1 and CO1 genes of S. japonicum in China.