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.