日本囊对虾卵母细胞发育过程中组织蛋白酶C比活性测定

组织蛋白酶C是一种溶酶样半胱氨酸蛋白酶，近年我们报道了组织蛋白酶C的表达与日本囊对虾(Marsupenaeus japonicus) 卵母细胞最后成熟阶段密切相关，本研究对卵母细胞发育主要不同时相特别是卵母细胞最后生理成熟过程进行了连续观察，测定了组织蛋白酶C在卵母细胞发育过程中的比活性。结果表明，日本囊对虾卵母细胞发育可划分为9个时相，即卵原细胞时相、核仁时相、周边核仁时相、初级卵黄发生时相、次级卵黄发生时相、皮质棒早期时相、皮质棒中期时相、皮质棒晚期时相、排卵期时相，生发泡的破裂是在排卵之前就已经发生；免疫印迹实验结果显示组织蛋白酶C蛋白只在卵母细胞最后成熟阶段即皮质棒发生时期表达，但酶活性测定结果表明组织蛋白酶C比活力在即皮质棒发生前后没有变化，酶活性较低，以上数据提示组织蛋白酶C可能与受精时皮质棒的释放以及受精卵外胶膜的形成有关。

Enzymatic activity measurement of cathepsin C during the oogenesis of kuruma shrimp Marsupenaeus japonicus

Cathepsin C is a member of the papain superfamily of lysosmal cysteine protease. Our previous studies showed that the expression of cathepsin C was involved in the final stages of oocyte maturation of the kuruma prawn (Marsupenaeuzs japonicus). In this study, the developmental process of the prawn oocytes was examined by light microscope and the cathepsin C activity was measured during oogenesis and final oocyte maturation. The prawn oocyte development was classified into 9 phases, namely, oogonium phase, plasmosome phase, peripheral nucleolus phase,primary vitellogenesis phase, secondary vitellogenesis phase, early cortical rod phase, middle cortical rod phase, late cortical rod phase and ovulation phase. The germinal vesicle breakdown occurred before ovulation. Immunolgical blot analysis showed that cathepsin C protein was expressed exclusively at the cortical rod stages in final oocyte maturation. However, the cathepsin C activity was low and no significant difference at cortical rod stages as compared with non-cortical rod stages, suggesting that cathepsin C might have a crucial role on regulating CR release and/or formation of a jelly layer during fertilization.