锯缘青蟹精子发生的超微结构

采用透射电镜观察锯缘青蟹精子发生过程中超微结构的变化，结果表明：精原细胞椭圆形，染色质分布于核膜周围，胞质中具嵴少的线粒体，内质网小泡等。初级精母细胞染色质呈非浓缩状，胞质中具众 内质网小泡，特殊的膜系及晶格状结构。次级精母细胞核质间出现由内质小泡聚集成的腔。

ULTRASTRUCTURE OF SPERMATOGENESIS IN THE CRAB SCYLLA SERRATA

Spermatogenesis in the crab Scylla serrata was examined using transmission electron microscopy. The spermatonium has an oval shape, in which there are dispersed chromatin, mitochondria and endoplasmic reticulum vesicles. The primary spermatocyte contains decondensed chromatin, a large amount of endoplasmic reticulum vesicles, special membrane system and crystalline lattices. In the secondary spermatocyte emerges a cavity which is formed by the aggregation of endoplasmic reticulum vesicles. The early polarized spermatid has a conspicuous proacrosomal vesicle at one pole, a dense apical condensate formed at the top of the vesicle. A homogeneous nucleus and some cytoplasm containing only the membrane system, mitochondria, etc. lie to the opposite pole. In the mid stage spermatid an invagination of the acrosomal vesicle membrane gives rise to the formation of the perforatorium, in which a shapeless tubule originates from the membrane system. The nucleus enlarges and the chromatin begins to arrange into fibers. In the late spermatid the nucleus differentiates into numerous slender arms, the spherial acrosome further develops into acrosomal tubule and acrosomal vesicle. The acrosomal vesicle includes an apical cap, a subcap zone, an inner layer and an outer layer. The mature sperm has a top like shape, the apical cap can be divided into three thin layers (two dense layers and one lucent layer). Outside of the outer layer are 2 3 lamellar structures. Microtubules of the perforatorium in the central cannal present a conical appearance.