大珠母贝精子发生超微结构变化的研究

STUDIES ON THE ULTRASTRUCTURAL CHANGES IN SPERMATOGENESIS OF PINCTADA MAXIMA JAMESON

利用透射电子显微镜观察大珠母贝（ＰｉｎｃｔａｄａｍａｘｉｍａＪａｍｅｓｏｎ）的精子发生，揭示了从精原细胞逐渐发育成精子的超微结构的变化．精原细胞附着在基膜上，切面为扁平多边形；细胞核内开始形成板层小体．在初级精母细胞质中出现了前顶体粒（直径约０，２μｍ）和中心粒；核内板层小体的大小和数量在次级精母细胞时达到高峰．在精子细胞时期，一些核内板层小体进入细胞质中与前顶体粒融合形成顶体，一些保留在精核中，另一些则随残余细胞质被丢弃．精子结构为典型的原生型，由头部（长约２．０μｍ）、中段（长约０．８μｍ，宽约１．４μｍ）和尾部（长６５～７０μｍ，直径０．２μｍ）构成．顶体位于精子头部前端，呈中空的圆锥体．精核呈桶状；中段包括２个中心粒和４个紧密排列的线粒体；尾部鞭毛断面为典型的９＋２结构．

The spermatogenesis of pearl oyster, Pinctada maxima Jameson was observed with electron microscope. The result indicate that the spermatogonium associate withthe hasal lamina of the testis,its nucleus contains some endonuclear lamellar bodies (ELB).A few of endoplasmic reticulums and some proacrosomal granuls appears in the spermatocyte. During the spermatid stage, some ELBs come into the cytoplasm to fuse with theproacrosomal granules and form proacrosomal vesicle which finally developes into an acrosome. The differenciated spermatozoon, which is of a typical primitive type, consists of thehead, the midpiece and the tail.