可口革囊星虫受精过程及早期卵裂的细胞学变化  

Cytological changes of fertilization and early cleavage in Phascolosoma esculenta

作　　者：竺俊全[1] 王武[2] 应雪萍[3] 许式见[1] 曾海祥[1] 陈惠群[1] 

机构地区：[1]宁波大学教育部应用海洋生物技术重点实验室,浙江宁波315211 [2]上海水产大学生命科学与技术学院,上海200090 [3]温州大学生命与环境科学学院,浙江温州325027

出　　处：《动物学报》2008年第2期290-298,共9页ACTA ZOOLOGICA SINICA

基　　金：浙江省自然科学基金(No.Y304096);浙江省教育厅项目(No.20051293;No.20040889);浙江省科技计划项目(No.2004C33095)资助~~

摘　　要：为探究可口革囊星虫(Phascolosoma esculenta)受精过程中精子入卵、极体排放、雌雄原核的形成与结合以及早期卵裂的特点,为胚胎发育机制研究奠定基础及指导人工育苗,显微观察了可口革囊星虫卵母细胞的形态;用荧光染色剂HOECHST33258对已固定的成熟卵及受精卵进行染色的方法,在荧光显微镜下观察了可口革囊星虫受精过程及第一与第二次卵裂的细胞学变化。成熟卵呈椭圆形,卵膜较厚,核区偏位,染色体排列整齐。在水温30℃-31℃、盐度23条件下,授精后5min-10min,精子完成入卵;授精后10min-20min,完成第一次减数分裂、释放第一极体;授精后20min-30min,完成第二次减数分裂、放出第二极体,部分受精卵的第一极体分裂为二;授精后30min-40min,雌、雄原核形成,并相互靠近向卵中央迁移;授精后40min-50min,雌、雄原核在卵中央结合成合子核;授精后50min-70min及70min-90min分别完成第一及第二次卵裂。可口革囊星虫的受精过程及早期卵裂的细胞学特点为:1)成熟卵是处在第一次减数分裂中期的初级卵母细胞,具有受精能力;2)精子入卵位点是随机的,存在多精入卵现象;3)雌、雄原核以融合方式结合成合子核;4)第一及第二次卵裂均为经裂、不等裂。In order to investigate features of penetration of sperm into the egg, the release of polar bodies, the formation and conjugation of the male pronucleus and the female pronucleus and changes during early cleavage, the fertilized eggs of Phascolosoma esculertta （Chen et Yeh ） were stained with a fluorescent reagent HOECHST 33258 were observed under a fluorescence microscope during fertilization and the first and second cleavage. The shape of ooeyte of Phascolosoma esculenta was examined histologically. The mature oocyte is oval, it has thick membrane, corner-localized nucleus and regularly arranged chromosomes. About 5 min - 10 min after insemination at water temperatures of 30℃ - 31℃ and salinity 23‰, the sperm penetrates the oocyte. About 10 min - 20 min later, the first meiosis is finished, with release of the first polar body. After 20 min - 30 min, the second meiosis is complete and the second polar body released. Part of the first polar bodies of fertilized oocytes divide into two second polar bodies. By 30 min - 40 min, the male and female pronuelei are formed, and later they move to the center of the oocyte and closer to each other. By 40 min - 50 min, both pronuclei fuse into the zygote and fertilization is complete. By 50 min - 70 min and 70 min - 90 min after insemination, the first and second cleavage are complete. There are several cytological characters of fertilization and early cleavage of Phascolosoma esculenta ： 1） the mature oocytes which can be fertilized are at the metaphase of the first meiosis; 2） the position where sperm enters the oocyte is random, and polyspermy exists in Phascolosoma esculenta ; 3） the male pronucleus and the female pronucleus unite with the zygote nucleus by the way of fusion; 4） the first two cleavages of the zygote are by unequal longitudinal division

关 键 词：可口革囊星虫 受精 卵裂 细胞学变化 

分 类 号：Q954.4[生物学—动物学]