Tyson John J, Novak Bela
Department of Biological Sciences, Virginia Polytechnic Institute and State University, Blacksburg, Virginia 24061, USA.
Curr Biol. 2008 Sep 9;18(17):R759-R768. doi: 10.1016/j.cub.2008.07.001.
The coordination of growth, DNA replication and division in proliferating cells can be adequately explained by a 'clock + checkpoint' model. The clock is an underlying cyclical sequence of states; the checkpoints ensure that the cycle proceeds without mistakes. From the molecular complexities of the control system in modern eukaryotes, we isolate a simple network of positive and negative feedbacks that embodies a 'clock + checkpoints'. The model accounts for the fundamental physiological properties of mitotic cell divisions, evokes a new view of the meiotic program, and suggests how the control system may have evolved in the first place.
增殖细胞中生长、DNA复制和分裂的协调可以通过“时钟+检查点”模型得到充分解释。时钟是潜在的周期性状态序列；检查点确保周期无误地进行。从现代真核生物控制系统的分子复杂性中，我们分离出一个体现“时钟+检查点”的简单正负反馈网络。该模型解释了有丝分裂细胞分裂的基本生理特性，引发了对减数分裂程序的新观点，并提出了控制系统最初可能是如何进化的。
