论文部分内容阅读
用透射电子显微镜研究了鲻鱼精子发生和精子形成过程 .结果表明 ,鲻鱼早期精巢有两种类型的精原细胞 ,即A型和B型 ,在B型精原细胞可见核旁有类核周体 (nuage) ,可视为精原细胞向初级精母细胞发育分化的一个重要标志 .初级精母细胞减数分裂早期同源染色体配对明显可见 ,精子细胞之间存在着间桥联系 .鲻鱼成熟精子的特点是细胞核呈马蹄形 ,核凹较浅 ,核前端无顶体 ,核内染色质呈粗颗粒状 ,核膜与质膜之间有较大的空隙 .中段较短 ,近端中心粒和远端中心粒互相垂直 .精子尾部细长 ,横切面为典型的“9+ 2”双联微管结构 ,两侧有侧鳍
The spermatogenesis and spermatogenesis were observed by transmission electron microscopy.The results showed that there are two types of spermatogonia in early stage of anchovy, namely type A and type B. In type B spermatogonia, The nuage may be considered as an important marker of the differentiation of spermatogonia to primary spermatocytes.Parental spermatocyte pairing early homologous chromosomes are obviously seen, there is a bridge between the spermatids. Fish mature sperm is characterized by a horseshoe-shaped nucleus, shallow nuclear concavity, no acrosome at the anterior end of the nucleus, chromatin in the nucleus being coarsely granular, and a large gap between the nuclear membrane and the plasma membrane. The grain and distal centrioles are perpendicular to each other.The tail of the sperm is slender and transverse, with a typical “9 + 2” double microtubule structure with lateral fins