An experimental study was carried out on the Mullerian duct cells, i.e. epithelial cells and stromal cells, treated with trypsin and isolated by Percoll gradient centrifugation. Then they were cultured separately. In order to observe the difference of cell death rate induced by Mullerian inhibiting substance (MIS) secreted from gonad, some cells were co-cultured with fetal testis or ovary in the same embryonic age. Other cells were used for immunocytochemistry at the electron microscopic level with anti-MIS serum as primary antibody and peroxidase labelled goat anti-rabbit IgG antiserum or streptavidin colloidal gold as secondary antibody to show the receptor localizations of MIS on epithelial cells and stromal cells. The results showed that the death rate of Mullerian duct epithelial cells induced by MIS secreted from testis was increased as compared with the control cells (P

The synthesis of cellular and nuclear basic proteins in the first generation of the repopulated pachytene spermatocytes (RPS) after the withdrawal of gossypol treatment and the normal control pachytene spermatocyte (CPS) were studied by the incorporation of ~3H-arginine into proteins. After treatment with gossypol for various periods of time, the synthetic activity for cellular protein in the RPS was slightly inhibited. In comparison to CPS, the inhibitory rate ranged from 12% to 26% (gossypol treatment for 3 to 12 weeks, respectively). However, the synthetic activity for nuclear basic protein in the RPS was drastically reduced in comparison to that of the CPS. The reductive rate ranged from 46％ to 61％ in RPS (gossypol treatment for 3 to 12 weeks, respectively).Gel electrophoretic separation of the basic protein extracted from normal pachytene cell indicated that the major basic proteins were nucleosomal linker and core proteins, i. e., histone H_1, H_(2a), H_(2b), H_3 and H_4, and with a lesser amount of spermspecific BP and X_1 proteins. In the RPS, the synthesis of sperm-specific proteins(BP and X_1) and core histones (H_(2a) and H_4) reduced markedly.Finally, the effect of gossypol on the ratio change of nuclear basic protein to DNA in RPS and its relation to nucleosomal spacing and chromatin structure are discussed.