Studies On The Inherited Character Of Reproductivecell And Somatic Cell Of Schistosome Japonicum

Objective To prepare chromosome on reproductive cell and somatic cell of Schistosoma japonicum, to analyze the karyotype and character of C-band and G-band, observe the morphological character of chromosome on scanning electron microscope in order to further recognize the chromosome structure of Schistosoma japonicum.Method After being injected colchicine to Jimpy mice, collected worm and sliced the testis rapidly ,then treated the gonadal cells of S.japonicun by usual air drying method to prepare chromosome. Some chromosome samples were dried 3 days at room temperature then treated by HCl solution, saturation barium hydroxide solution, 2×SSC solution, stained and observed C-band. Prepared G-band on some slides by enzyme digestion and analyzed the character of them. After symboling the chromosome on light microscope then spurted gold and observed by scanning electron microscope.Result (1) The chromosome number of reproductive cell of S.japonicun is 8, and the karyotype is 2m + 3Sm + 2St + sex chromosome. According to Levan's standard, there are three groups in reproductive cell of S.japonicun, including metacentric chromosome, submetacentric chromosome and Subtelocentric chromosome.(2) The number of somatic chromosome of S.japonicun is 16, the karyotype is 4m + 6Sm + 4St + 2sex chromosome, and it is conformity with reproductive cell. The character of C-band is that each chromosome has centromeric band and the formula is 2n= 5CI+ + 4CI+ + 3CI + 2CT +2CT+. The character of G-band is that, each arm of No.1 has one banding. Short arm of No.2 has one banding and the long arm has two bandings. Short arm of No.3-4 has one banding and the long arm has four bandings. Short arm of No.5-7 has one banding and the long arm has two bandings. Short arm of No.8 has two bandings and the long arm has four bandings.(3) Observed by scanning electron microscope, it is clear that there is helical structure on chromosome which had been digested by enzyme and the surface is smooth on chromosome which didn't deal with enzyme.Conclusion This study method can prepare chromosome on meiotic mitosis and karyomitosis of S.japonicum successfully and gain characteristic C-band and G-band stripe. Directly spurt gold method can observe chromosomes clearly.