缢蛏Sinonovacula constricta卵子发生的超微结构分析

Ultrastructural analyses of oogenesis in Sinonovacula constricta

本文描述了缢蛏卵子发生过程细胞学和超微结构的特征。在卵黄发生前期,卵母细胞胞质中存在着核质外排小体和大量的核糖体。在卵黄发生期,卵质中可见发达的内质网、环孔瓣状体和大量的线粒体及高尔基体等;卵核上有核膜泡和核膜小管的结构,并可观察到核孔数目大量增加。文中讨论了上述几种结构在卵子发生过程中的作用以及它们之间的关系。

The cytological features and ultrastructures of the germ cells (including oogonia, previtellogenic and vitellogenic oocytes)in Sinonovacula constricta (Lamarck) are described. There are scarcely deve loped organelles in cytoplasm of oogonium,and the chromatins in oogonium nucleus appear clumped and electrodense. At previtellogenic stage,most chromatins in nuclei of oocyte become floccular and diffused. Besides a large number of ribosomes,several filar-granular dense masses.called 'nucleoplasm extruded bodies',could be observed in cytoplasm of the oocytes at previtellogeni(?) stage. Some blebs and tubular invaginations of nuclear envelope,and various developed organelles occur in vitellogenic oocytes. Sometimes,some cisternae of rough endoplasmic reticulum connect with annulate lamellae, even become mixed with them.and vice versa. A small piece of annulate lamellae also could be found among the cisternae of rough endoplasmic reticulum, which implies possible dynamic alternations between these two organelles. The functions of some submicroscopic structures and relationships among them are discussed.