Abstract
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.
Highlights
The early stages of embryo development require the integration of two separate design principles: a network that generates sustained oscillations and a control mechanism that produces robust spatial synchronization
Simple diffusion alone is insufficient to communicate the stage of the cell cycle over typical embryonic length scales (0.1–1 mm), it has been proposed that the combination of certain molecular species in a developing embryo may be regarded as an active medium [2]
What would be the biological consequences of this behavior? How do embryos avoid chaos? Our work provides potential answers to these questions: Chaos would lead to an unpredictable patchwork of cell divisions across the embryo - clearly a fatal defect in development
Summary
The early stages of embryo development require the integration of two separate design principles: a network that generates sustained oscillations and a control mechanism that produces robust spatial synchronization. Simple diffusion alone is insufficient to communicate the stage of the cell cycle over typical embryonic length scales (0.1–1 mm), it has been proposed that the combination of certain molecular species in a developing embryo may be regarded as an active medium [2]. Active media allow for the transmission of information over large length scales at rates far greater than allowed by simple diffusion. The existence of an active medium coupled to an oscillatory system does not guarantee spatial synchrony: active media can give rise to complex spatial patterns, including chaos [5]. If the embryo functions as an active medium during development, what guarantees that oscillations will be uniform and not spatially patterned or even chaotic?
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
