title: Molecular processes and radiosensitivity.
abstract: BACKGROUND
  DNA double-strand breaks (DSB) are the most genotoxic lesions induced by ionizing radiation. At least 2 different pathways for DSB repair have been identified, homologous and non-homologous recombination.
  
  
  METHODS
  Studies on X-ray-sensitive mutants have led to the identification of several genes involved in processing of DSB in bacteria, yeast and mammalian cells.
  
  
  CONCLUSIONS
  In mammalian cells non-homologous recombination is the main pathway for DSB repair, while the role of homologous recombination in DSB repair awaits clarification. It is known that, in addition to DNA repair, other safeguards control the human cellular response to ionizing radiation, such as cell cycle regulation and mechanisms involved in scavenging of free radicals produced by ionizing radiation.
authors.affiliation: MGC-Department of Radiation Genetics and Chemical Mutagenesis, Leiden University, The Netherlands. Zdzienicka@rullf2.MedFac.LeidenUniv.nl
authors.forename: M Z
authors.initials: MZ
authors.lastname: Zdzienicka
mesh_terms: D004247:DNA / Q000528:radiation effects; D004249:DNA Damage; D004260:DNA Repair; D004274:DNA, Recombinant; D006801:Humans; D008967:Molecular Biology; D011832:Radiation Injuries; D011836:Radiation Tolerance
chemical_list: D004274:DNA, Recombinant; D004247:DNA