褐菖■精细胞晚期的变化及精子结构研究

本文研究卵胎生硬骨鱼褐菖（Ｓｅｂａｓｔｉｓｃｕｓｍａｒｍｏｒａｔｕｓ）精细胞的成熟变化和精子结构。褐菖精细胞发育晚期已具有硬骨鱼类精子的结构雏形：细胞核的背面较平坦，腹面稍外鼓，呈弧面；染色质浓缩成团块状，核的腹侧和后端的染色质较致密；中心粒复合体由近端中心粒和基体组成，近端中心粒和基体排成“Ｌ”形；近端中心粒向细胞核的背侧伸出中心粒附属物，中心粒附属物由９条微管组成，９条微管围成一筒状结构，类似轴丝。在晚期精细胞形成精子的过程中，中心粒附属物和近端中心粒相继退缩以至消失不见，同时细胞核后端的形状也随着发生变化。中心粒附属物和近端中心粒的相继消失可以看作是成熟的最后标志。精子的中心粒复合体由基体及其上方的基体帽组成，袖套接于核的后端，其中约有３０～４０个线粒体；鞭毛从袖套腔中伸出，鞭毛的中心结构是轴丝；轴丝外方为细胞质形成的侧鳍，在鞭毛的近核段，轴丝两侧的侧鳍较宽且不对称。

A STUDY ON THE CHANGES DURING THE MATURATION OF THE LATE SPERMATID AND THE STRUCTURE OF THE SPERMATOZOON OF Sebastiscus marmoratus

The late spermatid of ovoviviparous teleost, Sebastiscus marmoratus (Cuvier et Valenci ennes) possessed the approximate morphology of mature spermatozoon. The dorsal side of the nucleus was flat wheras its ventral side protruded outwards slightly The chromatin condensed into wads. At its ventral part and posterior end, the chromatin was more compacted. The cen triolar complex consisted of proximal centriole and basal body. The proximal centriole was per pendicular to the basal body, thus, the complex was L shaped. A centriolar adjunct stretched out of the proximal centriole and pointed towards the dorsal side of the nucleus. The centriolar adjunct was composed of 9 microtubules.They formed cylinder shape as the axoneme. During the process of transforming into spermatozoon, the centriolar adjunct and proximal centriole shrank back in succession, and finally disappeared completely. At the same time, the changes of the shape of the posterior end of the nucleus took place. The disappearing of the centriolar adjunct and proximal centriole in succession might be considered as a sign of being mature com pletely of the spermatid. The centriolar complex of the spermatozoon consisted of basal body and basal body cap which was between the basal body and the nuclear membrane. The sleeve was connected to the posterior end of the nucleus. There were about 30-40 mitochondria in the sleeve. The flagellum stretched out of the central space of the sleeve. The central structure of the flagellum was axoneme. There was one lateral fin at each side of the axoneme. At the proximal piece of the flagellum the lateral fins beside the axoneme were broad and asymmetrical.