锯缘青蟹卵子发生的超微结构研究

锯缘青蟹的卵子发生可划分为卵原细胞，卵黄发生前期和卵黄发生期卵母细胞三个时期，卵原细胞核大而圆，卵质稀少，胞器以滑面内质网为主。卵黄发生前的卵母细胞核显著膨大，部分核内可见到同源染色体的联会现象：卵质细密，出现核仁外排物和大量的核糖体，粗面内质网，线粒体和自噬泡，卵黄发生的卵母细胞核膜上核孔密集；卵质中各种胞器高度发达，参与形成卵黄粒和脂滴；细胞出现微吞饮活动并形成卵黄膜，细胞外围单层滤泡细胞，本

Ultrastructural Studies on Oogenesis of Scylla serrata

The oogenesis of the mud crab,scylla serrata,can be divided into threestages,i.e. oogonium,previtellogenic oocyte and vitellogenic oocyte. Besides a large andround nucleus,oogonium mainly contains sacs of smooth endoplasmic reticulum. The nucleiof previtellogenic oocyte become markedly swollen,in some of them, the synapsis betweenhomogeneous chromosomes could be observed.A this stage,a large rumber of ribosomesand well-developed rough endoplasmic reticula,mitochondria and autophagic vacuoles appearin progressly increasing cytoplasm. Numerous nucleopores and various developed organellesin vitellogenic oocytes indicate active metabolism and yolk formation at the stage. Meanwhileactive microphagocytosis could be seen along the ooplasma membrane while the vitellin mem-brane forms on the surface of vitellogenic oocyte. The changes of the structure in oocytes,and the origin and functions of the autophagic vacuole in oocyte are also discussed.