Cameron I L, Bols N C
J Cell Biol. 1975 Dec;67(3):518-22. doi: 10.1083/jcb.67.3.518.
The ciliated protozoan, Tetrahymena pyriformis strain GL-C, has been used to study the effect of cell population density during starvation on the synchrony obtained after refeeding and on the number of cells arrested in G2 phase of the cell cycle. At high cell densities two peaks of division indices were observed after refeeding while only one was observed at low cell densities. Cell division began earlier in cultures starved at high cell densities. Most importantly, the proportion of cells in G2 was considerably higher in populations starved at high cell densities. When tritiated thymidine was present during the refeeding period, radioautographs of cell samples at different times showed that the first cells to exhibit division furrows contained unlabeled nuclei. The first peak in the division index after refeeding was observed only at higher cell densities and is attributed to the cells arrested in G2. These results suggest that Tetrahymena is an excellent organism to study the concept of resting stages in the cell cycle and their control.
纤毛原生动物梨形四膜虫GL - C株已被用于研究饥饿期间细胞群体密度对再投喂后获得的同步性以及细胞周期G2期停滞细胞数量的影响。在高细胞密度下，再投喂后观察到两个分裂指数峰值，而在低细胞密度下仅观察到一个峰值。在高细胞密度下饥饿培养的细胞中，细胞分裂开始得更早。最重要的是，在高细胞密度下饥饿的群体中，处于G2期的细胞比例要高得多。当在再投喂期间存在氚标记的胸腺嘧啶核苷时，不同时间的细胞样品放射自显影片显示，最早出现分裂沟的细胞含有未标记的细胞核。再投喂后分裂指数的第一个峰值仅在较高细胞密度下观察到，并且归因于停滞在G2期的细胞。这些结果表明，四膜虫是研究细胞周期中静止期概念及其调控的优秀生物体。
