日本鳗鲡精子形成过程中的形态结构特点

本文通过扫描电镜、透射电镜观察了日本鳗鲡（Anguilla japonica）精子形成的特殊过程及产生细胞器的特殊结构。由精细胞变成精子包括四个特殊阶段，即经过早期、中期、晚期和精子期．最后形成正常成熟的精子．（1）早期阶段：其特征是细胞核由椭圆形逐步变成长条形；在细胞核的一端．有一个大的圆的染色较浅的形状似球形的特殊结构，约占细胞核的三分之一，其内含有少量着色深的颗粒状和线条状物质，外面由质膜包被着与细胞核分开，该结构和细胞核的外层还有一层质膜包着形成一个整体：精子早期阶段没有形成独立的线粒体和中心粒。（2）中期阶段：其特征是细胞核呈长条形．有球形结构的一端成为细胞核的上端，无球形结构的一端成为细胞核的下端，在下端出现鞭毛的原基；球形结构伴随着精子的发生也发生变化，内部逐步分化出中心粒和线粒体等细胞器：在细胞核的中段有明显的溶酶体分布。（3）晚期阶段：其特征是细胞核呈“眉形”或“新月形”．中心粒从球形结构中释放出来形成独立结构．球形结构中只剩下还没有形成独立结构的线粒体：在细胞核的下端鞭毛的原基处长出较长的鞭毛，这时期的精子已具有运动能力。（4）精子期：其特征是细胞核呈圆形，中心粒位于植入窝内，线粒体分布在细胞核的下面．在线粒体的下面有袖套腔形成，此时形成的鞭毛为“9＋2”结构。日本鳗鲡精子经过四个时期的变态．才能形成真正成熟的精子。

MODALITY AND STRUCTURE OF JAPANESE EEL(ANGUILLA JAPONICA)DURING SPERMIOGENESIS

The special process and special structure which bring organelle during the spermiogenesis of Japanese eel, Anguilla japonica were observed by scanning electron microscope and transmission electron microscope. The process which spermatoblast became sperm including four special stages, the early stage, the middle stage, the later stage and the spermic stage, then came into being a normal mature sperm. In the early stage, cell nucleus became long form gradually by the oval form. In one side of the cell nucleus, there was a big and special globoid structure dyeing lower, account for 1/3 of cell nucleus cubage. It contains a little of deep dyeing grain form and the lines form material, the outside is wrapped by plasmalemma separated with the cell nucleus, the outside of that structure and cell nucleus still lay a plasmalemma. The spermiogenesis of early stage did not form independent centriolar complex and mitochondria.
In the middle stage, the cell nucleus presented a long form with the globoid structure on the top of the nucleus, and the down side had no globoid structure where the flagellum primordium appears. The globoid structure changed with the spermiogenesis. The inner part of the globoid differentiated a centriolar complex and mitochondria step by step. The lysosomes distributed in the medium segment of the cell nucleus obviously.
In the late stage, the cell nucleus was similar with the shape of eyebrow or crescent. The centriolar complex released from the globoid structure, then became an independent structure. There were mitochondria which had not become the independent structure still in the globoid structure. Under the karyon, there was flagellum primordium where sent a rather long flagellum. The flagellum formed a typical ＂9＋0＂ microtubular structure at that time. The spermatozoa in this phase has movable ability.
In the spermic stage, the cell nucleus was round in shape. The centriolar complex was inside implantation fossa. Mitochondria were under karyon. And under the mitochondria was the c