四川华鳊精子发生显微及超微结构观察

对四川华鳊(Sinibrama taeniatus)精子发生过程进行了显微及超微结构观察。结果显示:在四川华鳊精子发生过程中,生精细胞嗜碱性逐渐增强,细胞体积渐小;精原细胞可分为两种,二者在显微及超微结构上均有明显区别;从精原细胞分裂开始就出现胞质不完全分裂,相邻细胞通过细胞质桥连接,并在精子细胞变态中后期消失;初级精母细胞核仁在减数第一次分裂开始后会逐渐消失;精子细胞变态过程中可观察到互相垂直的基体和近端中心粒,晚期出现中心粒附属物并在精子成熟前逐渐萎缩至消失,近端中心粒也在精子成熟时消失;四川华鳊精子头部近圆形或稍不规则,无顶体,核空泡小,核凹窝不发达,尾部具两侧对称的侧鳍,轴丝为"9+2"双联体微管结构。

Microstructure and ultrastructure observation of spermatogenesis in Sinibrama taeniatus

The spermatogenesis of Sinibrama taeniatus was investigated by histological and ultrastructural methods in the present study. The results showed that the volume of germ cells gradually decreased with the strengthen of cell basophilia in the process of spermatogenesis. Spermatogonia cells could be distinguished as two types by their microscopic and ultrastructural characteristic. The incomplete division of cytoplasm dated from the spermatogonia cells and the intercellular cytoplasm bridge occurred to contact adjacent cells which would disappear in the late stage of spermiogenesis. The nucleolus of primary spermatocytes would eventually disappear after the first meiosis. The basal body and proximal centriole were observed to be perpendicular to each other during spermiogenesis, and the centriolar appendage arose in the late stage and disappeared with proximal centriole before sperm maturation. The head of S. taeniatus sperms were nearly round or slightly irregular with small nuclear vesicles, undeveloped nuclear pocket, symmetrical lateral fin and no acrosome. In addition, the axoneme of sperm was “9+2” duplex microtubule.