Lewis-Sigler Institute for Integrative Genomics, Princeton University, Princeton, New Jersey, United States of America.
PLoS Comput Biol. 2011 Jul;7(7):e1002109. doi: 10.1371/journal.pcbi.1002109. Epub 2011 Jul 14.
Although many of the core components of the embryonic cell-cycle network have been elucidated, the question of how embryos achieve robust, synchronous cellular divisions post-fertilization remains unexplored. What are the different schemes that could be implemented by the embryo to achieve synchronization? By extending a cell-cycle model previously developed for embryos of the frog Xenopus laevis to include the spatial dimensions of the embryo, we establish a novel role for the rapid, fertilization-initiated calcium wave that triggers cell-cycle oscillations. Specifically, in our simulations a fast calcium wave results in synchronized cell cycles, while a slow wave results in full-blown spatio-temporal chaos. We show that such chaos would ultimately lead to an unpredictable patchwork of cell divisions across the embryo. Given this potential for chaos, our results indicate a novel design principle whereby the fast calcium-wave trigger following embryo fertilization synchronizes cell divisions.
尽管胚胎细胞周期网络的许多核心组成部分已经阐明，但胚胎在受精后如何实现稳健、同步的细胞分裂仍是一个未被探索的问题。胚胎可以通过哪些不同的方案来实现同步？通过将先前为青蛙 Xenopus laevis 的胚胎开发的细胞周期模型扩展到包括胚胎的空间维度，我们为触发细胞周期振荡的快速受精引发的钙波确立了一个新的作用。具体来说，在我们的模拟中，快速钙波导致细胞周期同步，而慢速钙波导致完全的时空混沌。我们表明，这种混沌最终会导致胚胎中细胞分裂的不可预测的拼凑。考虑到这种混沌的可能性，我们的结果表明了一个新的设计原则，即胚胎受精后快速钙波触发使细胞分裂同步。
