Abstract: Objective To investigate the genetic evolutionary relationship among Schistosoma japonicum populations in different areas within Anhui Province. Methods Naturally Oncomelania hupensis were collected form the hilly / mountainous regions(Shitai County in Chizhou City) and swamp / lake areas( Daguan district in Anqing City,Zongyang County in Tongling City). Cercariae escaped from the infected snails obtained in diverse locality were used to infect laboratory-raised female BALB / c mice by dose of (50±3) cercariae in individual mouse. Then the mice were dissected 35 days after infection to collect the adult worms via portal vein perfusion technique. DNA was extracted from the adults to undergo PCR amplification,cloning and sequencing of the mitochondrial dehydrogenase 1( ND1) and cytochrome C oxidase subunit Ⅰ( COⅠ) gene fragments. The sequences were analyzed by bioinformatics software Dnasp 6. 0 and Mega X. Evolutionary trees were constructed using the neighbor-joining method with MEGA software ( version 10. 2. 2) to observe the evolution clues. Results Fifteen nucleotide variation sites in ND1 gene and 74 in COⅠ gene were identified in the samples obtained in three districts. The nucleotide diversity (Pi) of ND1 and COⅠ gene was 0. 004 7 and 0. 017 3,respectively. The variation of CO Ⅰ between these samples was a little higher than that of ND1 gene. Variable sites of ND1 and COⅠ genes and Pi were higher in the samples from swamp / lake areas than in those from hilly / mountainous regions. Samples from Shitai County were independent in the tree based on COⅠ gene,yet all of the samples were gathered together in the tree at the foundation of ND1 gene. Conclusion The genetic diversity is higher in S. japonicum from marshy regions than in that from hilly regions. The results indicated that there was some differences between the COⅠ gene of S. japonicum from hilly region and marshy region in Anhui province, and meanwhile there was no significant differences between the ND1 gene of these S. japonicum worms by now.

Key words: Schistosoma japonicum, Genetic variation, NADH dehydrogenase subunit 1 gene, Cytochrome C oxidase subunit Ⅰ gene, Anhui Province