[Restoration of DNA supercoiling in fibroblasts in the rat subjected to gamma ray or fast neutrons].
Nucleoid sedimentation analysis was applied to the study of DNA supercoiling repair in cultured FR 3T3 fibroblasts exposed to low doses of fast neutrons or gamma-rays. Supercoiling was fully restored in both instances upon post-irradiation at 37 degrees C, but the rate of repair of neutron-induced lesions was lower than that for gamma-rays. Non-repairable breaks were not evidenced at the neutral pH used. We suggest that the non-repairable alkali-labile sites evidenced by others in neutron-irradiated DNA do not prevent strand break rejoining and subsequent recovery of the tertiary DNA structure.
Giocanti
N
N
Institut Curie, Section de Biologie, Centre universitaire, Orsay.
Sabattier
R
R
Ekert
B
B
D000818:Animals; D004260:DNA Repair / Q000528:radiation effects*; D004278:DNA, Superhelical / Q000528:radiation effects*; D004305:Dose-Response Relationship, Drug; D004307:Dose-Response Relationship, Radiation; D004996:Ethidium / Q000494:pharmacology; D005214:Fast Neutrons; D005347:Fibroblasts; D005720:Gamma Rays; D006863:Hydrogen-Ion Concentration; D051381:Rats; D011919:Rats, Inbred Strains; D013997:Time Factors
D004278:DNA, Superhelical; D004996:Ethidium
Restauration du surenroulement de l'ADN de fibroblastes de rat soumis aux rayons gamma ou aux neutrons rapides.