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X-Ray-Induced DNA Double Strand Breaks in Polynucleosomes

  • F. Barone
  • M. Belli
  • E. Rongoni
  • O. Sapora
  • M. A. Tabocchini
Part of the NATO ASI Series book series (NSSA, volume 124)

Abstract

Most of the studies on DNA damage induced by ionizing radiations are based on the assumption that lesions are randomly distributed along the cellular DNA. However, Roti Roti et al. reported that the efficiency of gamma radiation in producing DNA thymine damage (tγ) depends on the amount of proteins associated with DNA (1). Since chromatin structure is not uniform in the genome and changes during replication and transcription, it seems reasonable to assume that different DNA regions may have different radiosensitivity. In fact, a non-random distribution in DNA damage was recently found by some authors. after gamma irradiation, Chiu et al. (2) observed that both single strand breaks (ssb) production and repair were greater in actively transcribing genes than in total nuclear DNA. Warters and Childers (3) found that the newly replicated DNA was hypersensitive to the induction of tγ-type damage. These findings have been related to the different accessibilities of DNA regions to diffusible radicals and repair enzymes, and point out the importance of the association of DNA with the protein component of chromatin.

Keywords

Single Strand Break Sedimentation Profile Micrococcal Nuclease Histone Octamer Diffusible Radical 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.

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References

  1. 1.
    J. L. Roti Roti, G. S. Stein, and P. A. Cerutti, Biochemistry 13:1900–1905 (1974).PubMedCrossRefGoogle Scholar
  2. 2.
    S. M. Chiu, N. L. Oleinick, L. R. Friedman, and P. J. Stambrook, Biochim. Biophys. Acta 699:15–21 (1982).PubMedCrossRefGoogle Scholar
  3. 3.
    R. L. Warters and T. J. Childers, Radiat. Res. 90:564–574 (1982).PubMedCrossRefGoogle Scholar
  4. 4.
    K. E. Van Holde and W. O. Weischet, in: “The Cell Nucleus-Chromatin, Vol. IV,” Academic Press, New York, pp. 75–105 (1978).Google Scholar
  5. 5.
    G. P. Van der Schans and J. B. Aten, Anal. Biochem. 32:14–30 (1969).PubMedCrossRefGoogle Scholar

Copyright information

© Springer Science+Business Media New York 1986

Authors and Affiliations

  • F. Barone
    • 1
  • M. Belli
    • 1
  • E. Rongoni
    • 1
  • O. Sapora
    • 2
  • M. A. Tabocchini
    • 1
  1. 1.Laboratorio di Fisica and Comparata ed EcotossicologiaIstituto Superiore di SanitaRomeItaly
  2. 2.Laboratorio di Tossicologia Comparata ed EcotossicologiaIstituto Superiore di SanitaRomeItaly

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