Yu C K, Sinclair W K
Division of Biological and Medical Research, Argonne National Laboratory, Argonne, Illinois 60439, USA.
J Natl Cancer Inst. 1967 Oct;39(4):619-32.
Synchronized Chinese hamster cell populations in vitro were X-irradiated at different stages of the cell cycle and examined at the next metaphase. Mitotic delay varied according to the stage of the cell cycle at the time of irradiation. It was greatest for cells irradiated in middle to late S, moderate for cells irradiated in G2, and least for cells irradiated in G1. It increased approximately linearly with dose (0.7 hr./100 rad for S cells and 0.3 hr./100 rad for G1 cells). Chromosomal aberration rates also depended on the stage of the cell cycle at which the cells were irradiated. Chromatid aberrations were induced mostly during G2 and S (more in early S than late S), while chromosome aberrations were induced mainly in G1. Total breaks after 500 or 750 R showed a minimum frequency in late S and a maximum frequency in G2. This form of response correlates, but only in a general qualitative way, with the dependence of survival on cell cycle stage previously reported. Mitotic delay has a dependence on cell cycle stage quite different from either chromosomal aberrations or survival.
体外同步化的中国仓鼠细胞群体在细胞周期的不同阶段接受X射线照射，并在下一个中期进行检查。有丝分裂延迟根据照射时细胞周期的阶段而变化。对于在S期中期至后期照射的细胞，延迟最大；对于在G2期照射的细胞，延迟适中；对于在G1期照射的细胞，延迟最小。延迟随剂量大致呈线性增加（S期细胞为0.7小时/100拉德，G1期细胞为0.3小时/100拉德）。染色体畸变率也取决于细胞接受照射时的细胞周期阶段。染色单体畸变主要在G2期和S期诱导产生（早期S期比晚期S期更多），而染色体畸变主要在G1期诱导产生。500或750伦琴照射后的总断裂在S期后期显示出最低频率，在G2期显示出最高频率。这种反应形式与先前报道的存活对细胞周期阶段的依赖性相关，但只是一般的定性相关。有丝分裂延迟对细胞周期阶段的依赖性与染色体畸变或存活情况有很大不同。
