title: Behaviour of annulate lamellae during the maturation of oocytes in the newt, Cynops pyrrhogaster.
abstract: The distribution of annulate lamellae, electron-dense masses, rough endoplasmic reticulum, and Golgi complexes in longitudinal sections of newt oocytes at several stages of progesterone-induced maturation was recorded with an electron microscope equipped with a drawing device. Annulate lamellae in full-grown oocytes occur in close contact with electron-dense masses and the nuclear envelope and elsewhere. Stacks of annulate lamellae increase in number for 6 h after progesterone treatment. Meanwhile, they segregate into three groups. The largest group, comprising about 75% of total stacks, forms a row parallel to and just beneath the oocytes cortex of both the animal and vegetal hemispheres, a second group is distributed in the middle area of the vegetal hemisphere, and a third group appears near the yolk-free cytoplasm formed at the vegetal side of the germinal vesicle during the maturation. About 6 h after progesterone treatment the annulate lamellae begin to disappear at their places of localization and none is found a few hours after germinal vesicle breakdown. No immediate fine-structural change in the cortical area follows the disappearance of subcortical annulate lamellae. The possible origins and fates of annulate lamellae in the maturing newt oocytes are discussed.
mesh_terms: D000818:Animals; D004721:Endoplasmic Reticulum / Q000648:ultrastructure; D005260:Female; D006056:Golgi Apparatus / Q000648:ultrastructure; D008854:Microscopy, Electron; D009865:Oocytes / Q000648:ultrastructure; D009866:Oogenesis / Q000187:drug effects; D009940:Organoids / Q000648:ultrastructure; D011374:Progesterone / Q000494:pharmacology; D012455:Salamandridae / Q000502:physiology*; D013997:Time Factors
chemical_list: D011374:Progesterone