刺参受精及早期胚胎发育过程的细胞学观察

采用HOECHST 33258染色荧光显微方法,对刺参成熟未受精卵以及受精过程中精子入卵、极体排放、雌雄原核的形成与结合、早期卵裂以及多精入卵等细胞学进行了研究。结果显示,刚产出的刺参成熟未受精卵呈圆形,核相处于第一次成熟分裂中期;在水温22~23 ℃、盐度29条件下进行受精,受精后12 min,完成第一次成熟分裂,释放第一极体;受精后20 min,大部分受精卵完成第二次成熟分裂,放出第二极体。受精后35 min,雌、雄原核开始在卵中央发生染色体联合;受精后80 min,部分受精卵完成第一次卵裂,受精后100 min,部分受精卵完成第二次卵裂。刺参在受精过程中存在极少数的多精入卵现象。

Cytological observations on fertilization and early embryonic development in sea cucumber Apostichopus japonicus

A series of characteristic cytological events during fertilization and early embryonic development in Apostichopus japonicus were studied by the fluorescence microscope with HOECHST 33258 stained.The results indicated that unfertilized mature eggs of A.japonicus were globular and remained at the metaphase of meiosis Ⅰ.At water temperature of 22-23 ℃ and salinity 29,sperms quickly attached to the surface of the egg after mixing of sperms and eggs.At 12 min after insemination,the first meiosis is finished,with release of the first polar body.Most of fertilized eggs released the second polar bodies at 20 min after insemination.About 35 min,the male and the female pronuclei associated with each other after their chromosomes formed respectively in the center of egg.The first and second cleavages finished at 80 min and 100 min respectively in fast developing fertilized eggs.Polyspermy phenomena were observed in the fertilization process in A.japonicus.