Nishimoto T, Takahashi T, Basilico C
Somatic Cell Genet. 1980 Jul;6(4):465-76. doi: 10.1007/BF01539150.
Cultures of ts BN75, a temperature-sensitive mutant of BHK 21 cells, show a gradual biphasic drop in [3H]thymidine incorporation together with an accumulation of cells having a G2 DNA content when incubated at 39.5 degrees. However, when higher (41 degrees - 42 degrees) nonpermissive temperatures were used, the major block was in S-phase DNA synthesis. The cultures of ts BN75 shifted to 42 degrees at the start of the S phase, cell-cycle progress was arrested in the middle of S, while under these conditions wild-type BHK cells underwent at least one cycle of DNA synthesis. When ts BN75 cells growth-arrested at high temperature with a G2 DNA content were shifted to the permissive temperature (33.5 degrees C), the restart of DNA synthesis preceded the appearance of mitotic cells. These data suggest that the ts defect of ts BN75 cells might affect primarily the S phase of the cycle rather than the G2 phase.
ts BN75是BHK 21细胞的温度敏感突变体，其培养物在39.5℃孵育时，[3H]胸苷掺入量呈逐渐双相下降，同时出现具有G2 DNA含量的细胞积累。然而，当使用更高（41℃ - 42℃）的非允许温度时，主要阻滞发生在S期DNA合成。在S期开始时将ts BN75培养物转移至42℃，细胞周期进程在S期中期停滞，而在这些条件下野生型BHK细胞经历至少一个DNA合成周期。当具有G2 DNA含量的ts BN75细胞在高温下生长停滞并转移至允许温度（33.5℃）时，DNA合成的重新启动先于有丝分裂细胞的出现。这些数据表明，ts BN75细胞的ts缺陷可能主要影响细胞周期的S期而非G2期。
