Spatial heterogeneity accelerates phase-to-trigger wave transitions in frog egg extracts

The activity of Cyclin B-Cdk1, a central regulator of the cell cycle, exhibits periodic oscillations, initiating the division of the cell during peak activity. This oscillatory behaviour is driven by an autonomous biochemical oscillator that orchestrates mitotic events. In spatially extended systems, oscillatory dynamics give rise to wave formation, which coordinates mitotic entry. This mechanism is essential for synchronized cell divisions in large embryos, such as those of Drosophila and Xenopus, which can reach millimeter sizes. However, the precise mechanisms by which these waves coordinate mitosis over space and time remain unclear.In this talk, we present experimental results reconstituting mitotic waves in vitro. We observe a transition from phase waves to trigger waves, which explained through mathematical modeling emphasizes the importance of transient dynamics and spatial heterogeneity. Our work reveals how phase and trigger waves contribute to the coordination of mitosis.

Presential in the seminar room. Zoom stream: https://us06web.zoom.us/j/98286706234?pwd=bm1JUFVYcTJkaVl1VU55L0FiWDRIUT09