Nicoloff H, Vitanov V, Molle E. Mutations in rDNA. 2. Effects of Actinomycin D on chromatid aberration induction in nucleolus organizer regions.
TAG. THEORETICAL AND APPLIED GENETICS. THEORETISCHE UND ANGEWANDTE GENETIK 1982;
63:161-167. [PMID:
24270765 DOI:
10.1007/bf00303701]
[Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/20/1982] [Indexed: 06/02/2023]
Abstract
A reconstructed karyotype of barley with all chromosomes interdistinguishable was treated with hydroxyurea (HU) and Actinomycin D (Act D). The distribution pattern of chromatid aberrations after treatment with HU alone is characterized by a marked preferential involvement in chromatid translocations of segments 36 (NOR of satellite chromosome 6) and 43 (NOR of satellite chromosome 7). Act D applied at the low concentration of 0.05 μg/ml (4.10(-8) M) before HU treatment, or combined with HU, was found to cause an apparent decrease of HU-induced aberration frequencies in NORs. The exchanges in both segments proved to be approximately a half lower after Act D application when compared to the respective controls (treatment with HU alone). A recovery period of 5 h between the prolonged pretreatment with Act D (15 h) and the HU treatment eliminated the effect of the drug. The possible dependence of mutation induction upon the transcriptional activity of rDNA in NORs after Act D application is discussed.
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