Siede W, Friedberg E C
Department of Pathology, Stanford University School of Medicine, CA 94305.
Mutat Res. 1990 Dec;245(4):287-92. doi: 10.1016/0165-7992(90)90158-g.
Synchronously dividing haploid yeast cells were UV-irradiated in various stages of the cell cycle after release from alpha-factor arrest. In confirmation of earlier results (Chanet et al., 1973), in wild-type strains G1/S phase cells were found to be the most sensitive and late S/G2 cells the most resistant. Stationary-phase (G0) cells were significantly more UV resistant than G1 cells. Strains defective in nucleotide excision repair lost enhanced resistance in the G2 phase and were most UV-sensitive in the G0 state. Reduced G2 resistance was also observed in rad6 mutants but not in rad9 mutants. After UV-irradiation in G1 phase rad9 mutant cells showed a reduced G1/S phase arrest.
从α因子阻滞释放后，处于细胞周期不同阶段的同步分裂单倍体酵母细胞接受紫外线照射。正如早期结果（Chanet等人，1973年）所证实的那样，在野生型菌株中，G1/S期细胞最敏感，而S期后期/G2期细胞最具抗性。静止期（G0）细胞比G1期细胞对紫外线的抗性明显更强。核苷酸切除修复缺陷的菌株在G2期失去了增强的抗性，并且在G0状态下对紫外线最敏感。在rad6突变体中也观察到G2抗性降低，但在rad9突变体中未观察到。G1期紫外线照射后，rad9突变体细胞的G1/S期阻滞减少。
