Kane D A, Kimmel C B
Institute of Neuroscience, University of Oregon, Eugene 97403.
Development. 1993 Oct;119(2):447-56. doi: 10.1242/dev.119.2.447.
The zebrafish midblastula transition (MBT) begins at cycle 10. It is characterized by cell cycle lengthening, loss of cell synchrony, activation of transcription and appearance of cell motility. Superceding a 15 minute oscillator that controls the first nine cycles, the nucleocytoplasmic ratio appears to govern the MBT. This timing mechanism operates cell autonomously: clones of labeled cells initiate cell cycle lengthening independently of neighbors but dependent on immediate lineal ancestors. Unequal divisions, when they occur, produce asymmetric cell cycle lengthening based on the volume of each daughter. During the several cycles after the MBT begins, cycle length is correlated with the reciprocal of the blastomere volume, suggesting a continuation of cell cycle regulation by the nucleocytoplasmic ratio during an interval that we term the 'MBT period'.
斑马鱼的中囊胚转换（MBT）始于第10个细胞周期。其特征为细胞周期延长、细胞同步性丧失、转录激活以及细胞运动性的出现。取代控制前九个细胞周期的15分钟振荡器，核质比似乎控制着中囊胚转换。这种计时机制是细胞自主运行的：标记细胞的克隆独立于相邻细胞启动细胞周期延长，但依赖于直接的直系祖先。不等分裂发生时，会根据每个子细胞的体积产生不对称的细胞周期延长。在中囊胚转换开始后的几个细胞周期中，细胞周期长度与卵裂球体积的倒数相关，这表明在我们称为“中囊胚转换期”的时间段内，核质比持续调控细胞周期。
