[Comparative analysis of the population polymorphism of human silver-staining chromosomal nucleolus organizer regions].

The population study of nucleus organizing regions (NOR) activity in individuals of Georgian nationality was carried out using the Ag-method. The results obtained were compared with those for other populations: Russian, Viena-Ulm, Estonian etc. The mean number of active NORs for Georgians is 9.0, which significantly exceeds analogous indexes for the rest of populations, except Viena-Ulm one. The population differences in the distribution of NOR activity and the ability to be stained was found for individual NORs. The lowest activity was registered in chromosome 14, the highest being observed for chromosomes 21 and 13. It is assumed that some mechanism exists that controls the level of general NOR activity in the cell.