| Popis: |
Radiation-induced DNA double-strand breaks are rejoined in homogenates and isolated nuclei of Physarum polycephalum. In agreement with results obtained previously for intact plasmodia, double-strand breaks are less extensively repaired in nuclei isolated from S-phase, as compared to G/sub 2/-phase, cultures. A corresponding propensity of DNA present in unirradiated nuclei of S-phase plasmodia toward breakage during incubation in vitro was observed. Repair of putative single-strand breaks, as ascertained from alkaline sucrose density-gradient centrifugation analysis, was not observed. The possible relationships between these phenomena are discussed. |
