title: [Nucleolus organizer region activity of human chromosomes in relation to age].
abstract: Ag-stained acrocentric chromosomes were cytogenetically studied in 20 individuals aged 20-50, 80 and in older ones. It is revealed that the number of Ag-positive nucleolus regions and association frequency of Ag-stained acrocentric chromosomes statistically decreased in the individuals of old age as compared with the middle-aged persons. This is supposed to be conditioned by heterochromatinization of the satellite stalks of the 13th, 21st and 22 d chromosomes in the process of ageing.
mesh_terms: D000328:Adult; D000368:Aged; D000375:Aging; D002478:Cells, Cultured; D002871:Chromosome Banding; D002901:Chromosomes, Human, 13-15 / Q000648:ultrastructure*; D002904:Chromosomes, Human, 21-22 and Y / Q000648:ultrastructure*; D005260:Female; D006801:Humans; D008214:Lymphocytes / Q000648:ultrastructure; D008297:Male; D008677:Metaphase; D008875:Middle Aged; D009697:Nucleolus Organizer Region / Q000648:ultrastructure*; D014158:Transcription, Genetic
vernacular_title: Aktivnost' iadryshkoobrazuiushchikh raĭonov khromosom cheloveka v zavisimosti ot vozrasta.