title: [Electron-microscopic study of the nuclear membrane of the PKEV cells during mitosis. 1. The breakdown of the nuclear membrane (prophase, prometaphase, metaphase)].
abstract: An ultrastructural study on dividing PKEV cells provided a possibility to distinguish between certain stages of their desintegration. The changes preceding fragmentation of the nuclear envelope commence with desorganization of its structural components: vanishing of granular peripherial chromatin layer; appearance of the pores without central granules; formation of deep invaginations of the nuclear membranes. The desintegration of the nuclear envelope starts from the disapearance of many pores and the appearance of perforations almost of the same size. Simultaneously, the number of polysomes is reduced on the outer membrane of the nuclear envelope and in the cytoplasm. Specific features of the nuclear envelope being lost it becomes undistinguishable from the reticulum elements. On serial sections, no contacts were observed between chromosomes and membranous elements.
mesh_terms: D000818:Animals; D002843:Chromatin / Q000648:ultrastructure; D002875:Chromosomes / Q000648:ultrastructure; D004622:Embryo, Mammalian; D005260:Female; D007668:Kidney / Q000648:ultrastructure; D008854:Microscopy, Electron; D008938:Mitosis; D009685:Nuclear Envelope / Q000648:ultrastructure*; D011132:Polyribosomes / Q000648:ultrastructure; D011247:Pregnancy; D013552:Swine
chemical_list: D002843:Chromatin
vernacular_title: Elektronnomikroskopicheskoe izuchenie iadernoĭ obolochki kletok SPEV pri mitoze. 1. Raspad iadernoĭ obolochki (profaza, prometafaza, metafaza).