Coupling cellular oscillators: A mechanism that maintains synchrony against developmental noise in the segmentation clock

Abstract

A unique feature of vertebrate segmentation is its strict periodicity, which is governed by the segmentation clock consisting of numerous cellular oscillators. These cellular oscillators, driven by a negative‐feedback loop of Hairy transcription factor, are linked through Notch‐dependent intercellular coupling and display the synchronous expression of clock genes. Combining our transplantation experiments in zebrafish with mathematical simulations, we review how the cellular oscillators maintain synchrony and form a robust system that is resistant to the effects of developmental noise such as stochastic gene expression and active cell proliferation. The accumulated evidence indicates that the segmentation clock behaves as a “coupled oscillators,” a mechanism that also underlies the synchronous flashing seen in fireflies. Developmental Dynamics 236:1416–1421, 2007.