1994 Volume 11 Issue 2 Pages 239-246
The developmental expression of a zona pellucida antigen was examined by use of immunofluorescent stainings and electromicroscopic observations. A monoclonal antibody (MAb-5H4) which recognized an amino acid sequece of Cys-Thr-Val-Leu-Asp-Pro-Glu-Asn-Leu of pZPl was used for detection of the zona pellucida antigen.Electromicroscopic observations revealed that the zona pellucida antigen was deposited around oocytes in the primary follicles in a discontinuous pattern. The amount of the zona pellucida antigen increased according to the development of ovarian follicles in immunofluorescent stainings, suggesting that the zona pellucida antigen is produced continuously through the whole period of follicular development.The antigen was found not only outside but also inside of oocytes in primary follicles with 1-4 layers of granulosa cells. In addition, secretory vesicles containing the zona pellucida antigen were also observed in the cytoplasm of oocytes under the electromicroscope. It is thus concluded that during folliculogenesis the zona pellucida antigen was synthesized in the oocytes, transported to the plasma membrane by secretory vesicles, and was secreted.
