The relevance of the nuclear division cycle to radiosensitivity in yeast.

摘要: To investigate whether the nuclear division cycle could be related to cycle-specific changes in repair of ionizing radiation damage, we have determined survival curves after γ-irradiation samples taken frequently from synchronously dividing cultures Saccharomyces cerevisiae cells. Survival was low G1 and increased during S, reaching a maximum around end S phase, which maintained G2. The shape for later stages revealed rapid drop radioresistance individual A simple model formulated on assumption that is greatly enhanced by action an enzymatic mechanism requires duplicated but unsegregated DNA as substrate. By taking into account measurable age heterogeneity synchronous cultures, this shown fit data closely. For cell, increasing phase thus attributable rising fraction genome, whereas decrease at stage cell may interpreted due final physical separation sister chromatids. start latter event timed mitosis when nucleus begins move towards neck bud. are consistent with hypothesis high cells late G2 double-stranded breaks process involving recombination between