[Transcription activity of ribosomal genes in the pre- and postnatal periods of human development].

Transcriptional activity of silver-stained nucleolar-organizing region (NOR) of human chromosomes was studied in 50 medical abortuses at 6-12 weeks of gestation and 125 healthy individuals from 20 to 85-years-old. Transcriptional activity of rRNA genes was higher at the prenatal period of ontogenesis than at the postnatal period. Decline in total activity of ribosomal genes in both sexes was shown. Linear regression coefficients of the NOR activity in dependence of age satisfactorily predict the level of total NOR activity at the prenatal period of human development.