Cortical and zona reactions of heat-activated mouse eggs.
Oocytes collected from superovulated Swiss albino mice were activated by heat-shock and/or fertilized in vitro. Electron microscopy showed that the cortical reaction in heat-treated eggs was incomplete. Digestion of the zona pellucida of untreated, heat-treated and fertilized eggs by pronase showed that zona pellucida hardening did occur but was weaker in heat-treated than in fertilized eggs. Fertilizability of heat-treated eggs decreased 1.5 h after heating. We concluded that, in heat-activated eggs, changes occur at the zona and plasmalemma but they are not identical with those in fertilized eggs.
D000818:Animals; D005260:Female; D005307:Fertilization in Vitro; D006358:Hot Temperature; D051379:Mice; D008815:Mice, Inbred Strains; D008854:Microscopy, Electron; D009865:Oocytes / Q000648:ultrastructure*; D010063:Ovum / Q000502:physiology*; D013480:Superovulation; D015044:Zona Pellucida / Q000502:physiology*