title: Disappearance of cortical granules in rat ovum in vivo following fertilization.
abstract: Electron microscopical studies of the rat ova were carried out to clarify the pattern of disappearance of cortical granules following fertilization. When the posterior cap of the head of a spermatozoon was attahced to the vitelline membrane, cortical granules located beneath this membrane fused with this membrane to be decomposed or broken. Then their contents were discharged into the perivitelline space. The disappearance of cortical granules seemed to have started in an area around the site of the vitelline membrane to which spermatozoon was attached and spread soon all over the vitellus.
mesh_terms: D000818:Animals; D005260:Female; D005306:Fertilization; D010063:Ovum / Q000502:physiology / Q000648:ultrastructure*; D051381:Rats / Q000033:anatomy & histology* / Q000502:physiology