| 摘要: |
| 利用Hoechst 33258 染色、荧光显微镜观察方法, 对青蛤(Cyclina sinensis(Gmelin))受精和早期卵裂过程中的核相变化进行了细胞学研究。结果表明: 青蛤成熟未受精卵呈圆球形, 核内同源染色体排列整齐, 核相处于第一次成熟分裂中期。在水温25～26℃条件下进行人工授精, 精卵混合后, 精子迅速附着于卵子表面; 受精后5～10 min, 精子进入卵内并明显膨胀成球形; 分别在10～15 min、20～25 min受精卵进行两次成熟分裂, 排出第一、第二极体; 30 min 左右, 精、卵核体积膨胀, 形成弥散状的雌、雄原核; 35 min, 雌、雄原核在卵子中央发生原核联合, 染色体共同排列在纺锤体的赤道板上, 形成第一次有丝分裂的中期分裂相; 40～45 min, 受精卵进行第一次卵裂, 形成2 个大小不等的分裂球; 55～60 min, 第二次卵裂结束, 形成1 大3 小4 个卵裂球, 卵裂过程中的核相变化与第一次卵裂基本相同;70 min 左右, 胚胎开始第三次卵裂。另外, 在青蛤受精过程中发现了约1%的多精入卵现象, 且入卵精核均能形成雄原核, 但多精受精对成熟分裂和有丝分裂过程有很大影响, 往往造成成熟分裂紊乱和第一次卵裂染色体分离异常。 |
| 关键词: 青蛤(Cyclina sinensis(Gmelin) 受精 早期卵裂 多精入卵 细胞学观察 |
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| 基金项目:浙江省科技厅面上农业项目(2009C32020); 浙江省自然科学基金项目(Y3090007); 台州市科技计划项目(08KY07) |
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| Cytological change of nuclear behaviors of fertilization and early cleavage in Cyclina sinensis(Gmelin |
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| Abstract: |
| The artificial insemination experiment of Cyclina sinensis(Gmelin was carried out three times at Qingjiang Field Research Station of Zhejiang Mari-culture Research Institute from June to July in 2009. More than 1000 fertilized eggs and early embryos of C. sinensis(Gmelin in every developmental stage were fixed by 4% paraformaldehyde and stained by Hoechst 33258 to study the changes of nuclear behavior under the fluorescence microscope. The results of cytological observation indicated that unfertilized mature eggs of C. sinensis(Gmelin were globular (80～90 μm in diameter) and remained at the metaphase of the first maturation division. At water temperature of 25～26℃, artificial insemination was conducted. After mixing of sperms and eggs, sperms quickly attached to the surface of the eggs. At 5～10 min after fertilization, sperm has penetrated into cytoplasm of egg and activated the maturation division. The fertilized eggs released the first polar body at 10～15 min and the second polar body at 20～25 min. At about 30 min, sperm nucleus and the haploid female nucleus expanded to their maximum and developed into the male and female pronuclei which were loose and incompact. At 35 min, the male and female pronuclei matched into an association nucleus after their chromosomes formed in the center of egg. Subsequently, the chromosomes of association nucleus arranged on the metaphase plate of first cleavage. At 40～45 min, the chromosomes were separated equally into two daughter cells which were different in size. At 55～60 min, the second cleavage finished and formed four daughter cells, one big and three small. The process of the second cleavage was fundamentally similar to the first cleavage. At about 70min, the third cleavage started. In addition, the abnormal polyspermy about 1% in the process of fertilization was also observed. Though the polyspermy did not affect the formation of male pronucleus, it significantly affected the process of the maturation division and mitotic division as result of abnormal chromosome division. |
| Key words: Cyclina sinensis(Gmelin fertilization early cleavage polyspermy cytological observation |
