When the oocytes were fertilized in vitro,the microvilli on their surface became erect,the second polar body had a nucleus, and in the cytoplasm of the oocytes there were abundant organelles which were mainly distributed in the centre of the c ells.

• 受精后卵母细胞表面的微绒毛由倒伏而竖起,第二极体有核,细胞质中细胞器丰富,主要分布于细胞中心。