青蛤的受精细胞学观察

The cytological observation of fertilization in clam Cyclina sinensis

采用常规石蜡切片方法,用苏木精-伊红染色,在光学显微镜下观察青蛤Cyclina sinensis卵子受精和第一次卵裂的过程。青蛤的成熟卵处于第一次成熟分裂中期,此时可以接受精子入卵即受精。在水温23.2℃条件下,精卵混合6 min时精子开始入卵;混合15 min时,受精卵开始排出第一极体;混合21 min时,受精卵开始排出第二极体;雄原核在第二极体释放前形成,第二极体释放后很快形成雌原核,雌、雄原核逐渐在中央靠拢;42 min时,雌、雄原核融合成合子;50 min左右时,受精卵完成第一次卵裂,成为两个细胞。

The fertilization of clam Cyclina sinensis and the first cleavage were histologically and cytologically studied via paraffin section with haematoxylin - eosin staining under light microscope. The mature eggs of the clam were found to receive the sperm penetration （ i. e. fertilization） during metaphase of first meiosis. The sperm penetration was observed 6 minutes after the eggs and sperm were mixed at water temperature of 23.2℃. The first polar body was found 15 minutes and the second polar body 21 minutes after the eggs and sperm were met at 23.2℃. The male pronucleus was formed before releasing of the second polar body, and then the female pronucleus occurred quickly, the female and male pronuclei becoming together in the ovum center. The zygotes from the female and male nuclei were formed 42 minutes after the eggs and sperm were mixed, and the first cleavage （ two celled stage） was observed about 50 minutes after fertilization.