Schistosoma Japonicum: Aritificial Passage By Oncomelania Hupensis And DNA Polymorphism Of Atp6 Gene Among Isolates

Objects1. The Oncomelania hupensis infected by Schistosoma japonicum (S. japonicum) with artificial method is used to achieve the passage in door and satisfy other primary research of. S. japonicum.2. To examine sequence variation in the partial mitochondrial ATP synthase FO subunit 6 gene of S. japonicum. It is to provide foundation for studying the characterization and genetic structure of S. japonicum from different endemic origins of Hunan province.Methods1. Collect the mature eggs of S. japonicum by nylon net to hatch myracidiea. Infect snail at a ratio of 1:15～1:20 to obtain F1 generation infected snails. So does the F2 generation, F3 generation, F4 generation,.... Then, breed the snails by three different kinds of tank (slope tank, rice seeding bed tank, and ditch tank) stimulating nature environments.2. After extracting genomic DNA, atp6 gene was amplified with specific primers and screened by SSCP technique. Representative samples with variable banding patterns were selected for sequencing. DNAStar 5.0 and Mega 4.0 were used to analyze the sequences subsequently.Results1. Constructed three tanks and bred 30,20,40 thousand snails respectively, where snails survived in winter safely and brought forth immature snail. Especially, the mean rate of immature of the slope tank is 17.17%, accomplish the snails'reproduction artificially. There are 796 F1 generation,272 F2 generation and 362 F3 generation infected snails obtained. 2. Showed that partial atp6 gene of S. japonicum was 483 bp, and 17 mutation sites were detected (3.52%). Sequence variations for the partial atp6 were 0.0～1.3% between male and female parasites, and 0.0～1.5% among isolates from different geographical origins. Phylogenetic analysis revealed that S. japonicum in Hunan province could not be clustered in accordance with related geographic origins.Conclusion1. Constructed three tanks stimulated nature environments, which can satisfied the need of the further study of the S.japonicum passed indoor. It is come true that F1 generation, F2 generation, F3 generation of S.japonicum can pass indoor, which created conditions to the research of genetic variation and origin of S.japonicum.2. Sequence variation in apt6 gene among S.japonicum in Hunan province existed to a certain extent. Whether it was caused by the selection pressure of environment, it is worthy of intensive study.