Abstract: To observe and compare the differences of protein fractions of tissue and serum at different time points after cercariae infecting Microtus fortis and mice. The liver, spleen, lung and serum were collecting from cercariae infecting Microtus fortis at different time points (0, 7, 12, 45 days post-infection) and mice (0, 7, 12, 45 days post-infection) respectively. The individual soluble proteins were separated by SDS-PAGE and stained with kaomasi blue R-250. The band sizes and their differences were analyzed. Results showed that the 150 ku proteins fractions in liver was more obvious and high expressed after 7, 12 days post-infection in mice than in Microtus fortis; the 40 to 50 ku proteins fractions of spleen was high-expressed after cercariae infecting Microtus fortis; the same fractional protein of lung in Microtus fortis show conspicuous change than other time points; the immunoglobulin in serum of mice was increased significantly afer cercariae infecting. There were differences of protein fractions in tissue and serum at different time points after cercariae infecting Microtus fortis and mice. The 150 ku proteins fractions in liver and serum of Microtus fortis was characterized and higher expressed than other animals. It may be an important effective molecule against schistosoma japonicum infection in Microtus fortis.

Key words: Microtus fortis; Schistosoma japonicum; protein fraction; serum protein