Zebrafish Posterior Lateral Line Organogenesis Regulation by Notch Signaling

Abstract

Organ morphogenesis depends on the precise orchestration of cell migration, cell fate specification and cell shape chages. Results in this thesis demonstrate that Notch signaling is an integral part of the feedback loop between Wnt and Fgf signaling that underlies the self‐organization of rosette‐shaped sensory organs in the zebrafish lateral line system. Notch cell autonomously induces apical constriction and cell adhesion downstream of Fgf signaling and organizes lateral line organs into rosettes independent of patterning cues normally provided by a Wnt/Fgf signaling system. We also show that the ectopic Notch signaling induces larger organs independently of proliferation and the Hippo pathway. Transplantation and RNASeq analyses revealed that Notch signaling induces cell adhesion and tight junction proteins that interact with cytoskeleton causing cells to self‐organize into fewer larger organs rather than several smaller ones. Thus, Notch plays an essential role in coordinating actomyosin induced cell shape changes and their transmission throughout the tissue via adhesion molecules.