山羊卵子受精及原核期胚胞质成分的微细结构研究

FINE STRUCTURE OF FERTILIZATION AND CYTOPLASMIC COMPONENTS OF THE PRONUCLEAR EMBRYOS IN THE GOAT

本研究用光镜和电镜观察到山羊卵子受精15～16小时后,大部分处在原核期。受精卵透明带表面和外层内,有许多多余精子。透明带表面的精子,有的正在发生顶体反应,穿入透明带的精子,在透明带表面上留有顶体反应小泡。穿入透明带的多余精子均滞留在外层,无一进入内层或卵周隙。受精卵皮质颗粒排放较彻底,有皮质颗粒残留处质膜上微绒毛较少。原核期合子皮质区分布着许多成群的带帽线粒体和一些滑面内质网小泡、卵黄泡和脂滴。原核周围聚集着发达的高尔基复合体、滑面内质网、线粒体和环孔板。文中讨论了受精卵这些形态变化的意义。

Light and electron microscopic observations revealed that most of the embryos collected 15-16 hours after fertilization were at the pronuclear stage. Many supernumerary spermatozoa were found on the surface and in the outer zone of the zona pellucida, but none of them got into the inner zone of the zona or the perivitelline space. Some spermatozoa on the zona surface were observed in acrosome reaction stage, and those penetrated into the zona always left some acrosome reaction vesicles behind on the surface of the zona. The fertilized ovum eliminated almost all of its cortical granules and where there were some granules left, in the area that the plasma membrane had fewer microvilli. The cortical cytoplasm of the pronuclear zygote was populated with clustered hooded mitochondria, SER vesicles, yolk vacuoles and lipid droplets. Directly surrounding the pronucleus were a variety of organelles including welldeveloped Golgi complex, SER, mitochondria and annulate lamellae. The significance of these morphological changes of the fertilized ovum was discussed.