Mutagenesis, Vol. 15, No. 6, 503-506,
November 2000
© 2000 UK Environmental Mutagen Society/Oxford University Press
N-Methyl-N-nitrosourea-induced DNA damage detected by the comet assay in Vicia faba nuclei during all interphase stages is not restricted to chromatid aberration hot spots
Institute of Plant Genetics and Crop Plant Research (IPK), D-06466 Gatersleben, Germany
The genotoxic effect of the monofunctional alkylating agent N-methyl-N-nitrosourea (MNU) on root-tip nuclei of the field bean, Vicia faba, has been tested by comparative application of three protocols of the comet assay. While the alkaline denaturation/alkaline electrophoresis (A/A) procedure proved to be most sensitive at low doses, the alkaline denaturation/neutral electrophoresis (A/N) procedure yielded an optimal doseresponse curve within a wider dose range. With the neutral electrophoresis without alkaline denaturation (N/N) procedure only minimal response was found. MNU-mediated single-strand breaks occurred in nuclei of all interphase stages. Detection of tandemly repeated FokI elements on comets by fluorescence in situ hybridization showed an average involvement of these heterochromatin-specific sequences in MNU-mediated single-strand breaks. This, together with previous results, suggests that the pronounced clustering of chromosomal aberrations in heterochromatic regions after treatment with S phase-dependent mutagens is mainly due to an error-prone interference of recombinative repair and replication in damaged basic repeats of large tandem repeat arrays.
1 To whom correspondence should be addressed. E-mail: schubert{at}ipk-gatersleben.de
![]()
CiteULike
Connotea
Del.icio.us What's this?
This article has been cited by other articles:
![]() |
F. M. Restivo, M. C. Laccone, A. Buschini, C. Rossi, and P. Poli Indoor and outdoor genotoxic load detected by the Comet assay in leaves of Nicotiana tabacum cultivars Bel B and Bel W3 Mutagenesis, March 1, 2002; 17(2): 127 - 134. [Abstract] [Full Text] [PDF] |
||||
