The Genetical And Immunological Researches Of The Intermediate Host Of Schistosoma Japonicum

Objective To establish method for collecting haemocytes of Oncomelania hupensis and study its morphology and immunological importance to further verify the merchanism how Schistosome japonicum,invade the snail and how it protect itself from infection; Using haemocytes of Oncomelania hupensis to prepare Chromosome facilitates us to study it's classification,hereditary character and to screen resistant strain.Methods Referring to the method of lymphocyte collection from peripheral lymphoid organ, suspension technique was used for collection of haemocytes from snails, which were then Giemsa stained and observed under microscope. Stained by gentian violet, number of haemocytes was counted and compared with that of conventional squashing method and needling method by ANOVA and Dunnett-t test. Supernatant from freeze thawing haemocytes was applied for the tests of immuno-precipitation, bacteriostasis, and phagocytosis. SDS-PAGE was used to analyze relative molecular mass of protein ingredients.Gel chromatography to purificate haemocyte peptite. RMBI1640 medium to culture haemocyte. Hameocyte of Oncomelania hupensis exposed to Colchicine was performed with following procedures: hypotesion,fixation,dropping slide,staining and finally reading under microscope.Results The main results are given as follows:(1) Four kinds of haemocytes were found: round cells with filiform filopodia, acidophilic and basophilic round cells both without filiform filopodia, and spindle cells. The average diameter of the 4 type cells was 10.93, 6.13, 6.08, and 11.06μm , and occupied 50%, 30%, 5%, and 15% respectively.(2) The mean of haemocytes received from suspension, squashing and needling methods was 15 000, 6 600 and 300/ml respectively. ANOVA analysis showed F=281.47, P<0.01, and Dunnett-t test revealed t1=15.67, P<0.01 between suspension and squashing methods, and t2=24.50, P<0.01 between suspension and needling method.(3) The supernatant of haemocytes showed precipitation with SEA,(4) The supernatant of haemocytes showed bacteriostase with Staphylococcus aureus and Escherichia coli,(5) The supernatant of haemocytes showed 86% phagocytosis and 46% bactericide to Candida albicans.(6) SDS-PAGE revealed approximate Mr 112 300, 107 100, 972 00, 73 500, 600 00, 12 000 of the protein ingredients of the haemocytes.(7) Gel chromatography showed two spinnacles of haemocytes peptide.(8) RMBI1640 medium failed in culturing haemocytes. (9) The chromosome number of Oncomelania hupensis in Yangzhong of Jangsu is 34, and it's karyotype formula is 14m+8Sm+8St+2t + sex chromosomes.Conclusions Large amount of haemocytes has been obtained from the snails by suspension method, and the cells show a variety of immunological activities. It's found that the method of chromosome preparation can help us to analysis karyotype of Oncomelania hupensis.