title: [Ultrastructure, form and number of fibrillar centers in the GO-period cells of a swine embryonic kidney tissue culture].
abstract: A study has been made of the structure, shape and number of fibrillar centers (FC), using serial ultrathin sections of pig embryo kidney cells in the G0-period. It is shown that FC are spherical, cup-shaped or slightly elongated structures containing fibrils 7-10 nm in diameter, and are surrounded by a dense fibrillar component irregular in shape. FC and a dense fibrillar component are referred to in the paper as a fibrillar complex. In the G0-period, the fibrillar complex contains one to three fibrillar centers. The total number of fibrillar centers exceeds that of nucleolus organizing regions (NOR's) which are always present in the cells being in period G0. On the other hand, the number of NOR's coincides with the total number of fibrillar complexes. It is concluded that in the PK-cells being in period G0 one NOR may form one to three FC.
mesh_terms: D000818:Animals; D046508:Culture Techniques; D007399:Interphase; D007668:Kidney / Q000648:ultrastructure; D008854:Microscopy, Electron; D008961:Models, Structural; D009697:Nucleolus Organizer Region / Q000648:ultrastructure*; D013552:Swine; D013997:Time Factors
vernacular_title: Ul'trastruktura, forma i chislo fibrilliarnykh tsentrov v kletkakh GO-perioda kul'tury tkani pochki émbriona svin'i.