Wnt signaling dominates in a leading zone (green), while FGF receptor activity dominates in a trailing zone (red). Wnt/ß-catenin signaling drives the expression of secreted FGF ligands; it also prevents a response to FGF in the leading cells by triggering the expression of Sef and Dusp6, inhibitors of FGF receptor activation. Activation of the FGF receptor in trailing cells causes proneuromasts to form. It also determines the expression of a diffusible antagonist of Wnt signaling, Dkk1b, which helps restrict Wnt/ß-catenin signaling to a progressively smaller leading zone. Both Wnt and FGF signaling promote cell proliferation in the posterior Lateral Line Primordium. FGF-dependent Amotl2a expression in the trailing zone inhibits proliferation determined by Yap1 and by ß-catenin. Black and red lines represent positive and negative regulatory interactions, respectively. Solid arrows represent intracellular regulatory interactions, while dashed lines represent interactions mediated by secreted factors.
|Acknowledgments:||ZFIN wishes to thank the journal eLIFE for permission to reproduce figures from this article. Please note that this material may be protected by copyright. Full text @ Elife|