title: Sensitivity of DNA synthetic phase to near-ultraviolet radiation: chromatid damage at early and late replication periods.
abstract: Syrian hamster embryo (SHE) cells were pulse-labeled with bromodeoxyuridine at various periods of the S-phase, and then irradiated with near ultraviolet (NUV) light. Observation of the radiated chromosomes in the subsequent metaphase stage revealed that the period between the second and fourth hour of the S-phase is most sensitive to radiation damage. The prevalent types of chromatid aberrations are 'gaps' and 'breaks'. The results strongly suggest that the detrimental effect of NUV-radiation on chromosomes depends primarily on the particular stage when radiation is applied.
mesh_terms: D000818:Animals; D001973:Bromodeoxyuridine / Q000494:pharmacology; D002842:Chromatids / Q000187:drug effects / Q000528:radiation effects*; D002869:Chromosome Aberrations; D006224:Cricetinae; D004247:DNA / Q000096:biosynthesis; D004261:DNA Replication / Q000187:drug effects / Q000528:radiation effects*; D008647:Mesocricetus; D008677:Metaphase / Q000187:drug effects / Q000528:radiation effects; D011840:Radiation, Nonionizing
chemical_list: D004247:DNA; D001973:Bromodeoxyuridine