Dynamics of zona pellucida formation by the mouse oocyte. An autoradiographic study

The dynamics of the synthesis of the mouse oocyte zona pellucida was studied using light microscope autoradiography after intrabursal injection of (3H) -fucose. Zona accretion occurred continuously from the inside, demonstrating that the oocyte itself elaborated all the raw material of the zona. The duration of zona synthesis corresponded to that of the oocyte growth phase. Zona secretion stopped one week before ovulation and there was no renewal of its material.