短尾鮠精子发生的超微结构研究

Studies on Ultrastructure of Spermatogenesis in Leiocassis brevicaudatus

用透射电镜观察了短尾鮠的精原细胞、初级精母细胞、次级精母细胞、精子细胞和精子的形态以及细胞核、拟染色体和线粒体等的结构变化规律．结果表明:精原细胞时期细胞器较丰富,到精子细胞后期,细胞器的形态和数量发生了较大变化;随着精母细胞的发育,核质凝聚程度逐渐增强．短尾鮠的精子具有椭圆的头部和复杂的中片,近侧中心粒和远侧中心粒靠近核的中央,鞭毛呈9+2轴丝结构,并具有由外膜折迭形成的波浪形的结构．表明短尾鮠精子发生中具有某些区别于其它鱼类精子的不同结构．

A transmission electron microscope was used to the study of the morphology of the spermatogonium, primary spermatocyte, secondary spermatocyte, spermatoblast and sperm in the spermary of the catfish （Leiocassis brevicaudatus Wu）. The changes of the structure of the chromatoid body, mitochondiurn, and nucleus in five developmental stages of the spermatogenesis were also studied. Plenty of organelles were observed in the spermatogonium. At later stages of spermatoblast development, the morphology and number of the organelles changed substantially. With the spermatocyte development the electron density in the chromatin showed a steady increase. The sperm differs in fine structure from those of other teleost fishes. It is of short round head and contains a complicated midpiece and possesses two centrioles. The mitochondria, distal centriole are shown in the section through the midpiece of the sperm. The axoneme has 9＋2 pattern and possesses undulating membrane. Because the fish is such an important species, the present investigation, therefore, sets forth a comprehensive and detailed fine structural study.