title: A new estimate of human ribosomal gene number.
abstract: Radioactively labelled DNAs (5 X 10(6) cpm/mug) complementary to human 18 S and 28 S ribosomal RNA were synthesized using RNA-directed DNA polymerase (EC 2.7.7.7). These complementary DNAs were used to measure human ribosomal gene numbers by two independent methods, both of which indicated numbers at least four-fold lower than those previously reported. First, the kinetics of the annealing of the complementary DNAs with total human placental DNA indicated that the number of both 18-S and 28-S ribosomal genes per haploid genome is approximately 50. Second, saturation experiments in which a constant amount of DNA was annealed with increasing amounts of complementary DNA also indicated that the number of 28 S ribosomal RNA genes in human placental and spleen DNA is is about 50 per haploid genome.
mesh_terms: D004247:DNA / Q000378:metabolism; D005260:Female; D005796:Genes; D006801:Humans; D007700:Kinetics; D009691:Nucleic Acid Denaturation; D009693:Nucleic Acid Hybridization; D010920:Placenta; D011247:Pregnancy; D012335:RNA, Ribosomal / Q000378:metabolism; D012194:RNA-Directed DNA Polymerase; D012156:Reticulocytes / Q000378:metabolism; D012270:Ribosomes / Q000378:metabolism; D013154:Spleen; D014158:Transcription, Genetic
chemical_list: D012335:RNA, Ribosomal; D004247:DNA; D012194:RNA-Directed DNA Polymerase