caa a22 4500 47709015X CHVBK 20180405111514.0 cr unu---uuuuu 170330e19960801xx s 000 0 eng 10.1007/BF02257274 doi (NATIONALLICENCE)springer-10.1007/BF02257274 Redistribution of ribosomal DNA after blocking of transcription induced by actinomycin D [Elektronische Daten] [Christian Schöfer, Klara Weipoltshammer, Marlene Almeder, Markus Müller, Franz Wachtler] We report on the effect of different doses and times of incubation of the cytostatic drug actinomycin D (AMD) on nucleolar morphology, rRNA gene transcription and rDNA gene localization usingin situ hybridization and the immunocytochemical detection of the human upstream binding factor (UBF) at the electron microscopic level in HeLa cells. Low doses of AMD (0.001 μg/ml, 30 min) selectively block rRNA gene transcription but alter neither nucleolar morphology nor the localization of rDNA with respect to the nucleolar components. Treatment with high doses of AMD (0.05 μg/ml, 1 h) resulted in a retraction of the rDNA out of the nucleolus in addition to the well-known blocking or rDNA transcription, total nuclear transcription and nucleolar segregation. Under these conditions accumulations of rDNA were found in patches of chromatin at the nucleolar periphery. We conclude that the blocking of rRNA gene transcription and the changes in nucleolar morphology, both induced by AMD at different doses, are independent phenomena. Rapid Science Publishers, 1996 electron microscopy nationallicence immunocytochemistry nationallicence in situ hybridization nationallicence nucleolus nationallicence upstream binding factor nationallicence Schöfer Christian the Histologisch-Embryologisches Institut der Universität, Schwarzspanierstrasse, 17 A-1090, Vienna, Austria aut Weipoltshammer Klara the Histologisch-Embryologisches Institut der Universität, Schwarzspanierstrasse, 17 A-1090, Vienna, Austria aut Almeder Marlene the Histologisch-Embryologisches Institut der Universität, Schwarzspanierstrasse, 17 A-1090, Vienna, Austria aut Müller Markus the Histologisch-Embryologisches Institut der Universität, Schwarzspanierstrasse, 17 A-1090, Vienna, Austria aut Wachtler Franz the Histologisch-Embryologisches Institut der Universität, Schwarzspanierstrasse, 17 A-1090, Vienna, Austria aut Chromosome Research Kluwer Academic Publishers 4/5(1996-08-01), 384-391 0967-3849 4:5<384 1996 4 10577 https://doi.org/10.1007/BF02257274 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/BF02257274 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Schöfer Christian the Histologisch-Embryologisches Institut der Universität, Schwarzspanierstrasse, 17 A-1090, Vienna, Austria aut NATIONALLICENCE 700 1- Weipoltshammer Klara the Histologisch-Embryologisches Institut der Universität, Schwarzspanierstrasse, 17 A-1090, Vienna, Austria aut NATIONALLICENCE 700 1- Almeder Marlene the Histologisch-Embryologisches Institut der Universität, Schwarzspanierstrasse, 17 A-1090, Vienna, Austria aut NATIONALLICENCE 700 1- Müller Markus the Histologisch-Embryologisches Institut der Universität, Schwarzspanierstrasse, 17 A-1090, Vienna, Austria aut NATIONALLICENCE 700 1- Wachtler Franz the Histologisch-Embryologisches Institut der Universität, Schwarzspanierstrasse, 17 A-1090, Vienna, Austria aut NATIONALLICENCE 773 0- Chromosome Research Kluwer Academic Publishers 4/5(1996-08-01), 384-391 0967-3849 4:5<384 1996 4 10577 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer