斑马鱼受精过程中原核的时空规律

斑马鱼的成熟卵子处于第2次减数分裂中期,精子通过受精孔进入卵内,精子入卵后,卵子被激活;受精后3min,精核位于卵质膜内侧边缘,处于凝集状态;受精后5min精核开始解凝;受精后8min,精核明显解凝,受精卵出现明显的精子星光.同时进入第2次减数分裂后期,之后排出第二极体;受精后10min,雄原核形成,具有双星光,此时,雄原核已位于胚盘中部;受精后15min雌原核已形成,雌、雄原核向胚盘中央靠近;受精后20min,雌雄原核开始接触;受精后30min,雌雄原核完全融合成为1个合子核;35min时,受精卵开始第1次卵裂;45min后分裂形成2个子核;50min时分裂为2细胞,60min时分裂为4细胞.

Apatial and Temporal Variations of Pronucleus of Zebrafish, Brachdanio rerio Ham During Fertilization

The spatio-temporal changes of the pronucleus during fertilized egg of zebrafish(Brachdanio rerio Ham) was depicted in detail in this paper.The fertilized eggs of the zebrafish were fixed in Bouin's solution and dehydrated by alcohol. Then the tissue sections were stained with hematoxylin and eosin. The thickness of the tissue sections was 6 to 8 micrometers. Before the sperm entering the egg,the mature eggs of the zebrafish remained at the metaphase of the secondary maturation division. The spermaster could be clearly seen and the second polar body was extruded about 8 minutes after inse mination which showed that the egg was developing into the anaphase of the secondary maturation division. 10 minutes after inse mination, the sperm nucleus became vesicular nucleus. 15 minutes after inse mination, the male pronucleus was observed and the female pronucleus was formed at the same time. 20 minutes after inse mination, the male pronucleus and the female pronucleus moved toward the center of the blastodisk, then fused with each other. 35 minutes after inse mination, the first cleavage was observed and the first cleavage furrow of the blastodisk appeared after 45 minutes. The first and second mitotic division were completed by 50 min and 60 min after inse mination ,and resulted in a 2-cell and 4-cell embryo being observed.