title: Ionizing radiation and DNA-chain elongation in ataxia telangiectasia lymphoblastoid cells.
abstract: DNA-chain elongation rates, determined by sedimentation analysis, were found to be similar in control and ataxia-telangiectasia lymphoblastoid cells. A gamma-radiation dose of 6 Gray, which had previously been shown to have a marked inhibitory effect on initiation of DNA replication, had no appreciable effect on elongation rates in either cell type. Elongation rates were also determined at 20 Gray of gamma-rays by pulsing cells with [3H]thymidine prior to irradiation to avoid anomalous sedimentation behaviour. At this radiation dose elongation was almost completely inhibited in control cells while little or no inhibition was observed in ataxia-telangiectasia cells. Deoxyribonucleoside triphosphate pool equilibration times were not altered at either dose.
mesh_terms: D001260:Ataxia Telangiectasia / Q000235:genetics*; D002460:Cell Line; D002472:Cell Transformation, Viral; D004247:DNA / Q000096:biosynthesis*; D004261:DNA Replication / Q000528:radiation effects*; D005720:Gamma Rays; D006801:Humans; D008214:Lymphocytes
chemical_list: D004247:DNA