摘要:The auditory sensory epithelium, composed of mechano-sensory hair cells (HCs) and highly specialized glial-like supporting cells (SCs), is critical for our ability to detect sound. SCs provide structural and functional support to HCs and play an essential role in cochlear development, homeostasis and repair. Despite their importance, however, surprisingly little is known about the molecular mechanisms guiding SC differentiation. Here, we provide evidence that in addition to its well-characterized inhibitory function, canonical Notch signaling plays a positive, instructive role in the differentiation of SCs. Using γ-secretase inhibitor DAPT to acutely block canonical Notch signaling, we identified a cohort of Notch-regulated SC-specific genes, with diverse functions in cell signaling, cell differentiation, neuronal innervation and synaptogenesis. We validated the newly identified Notch-regulated genes in vivo using genetic gain ( Emx2 Cre /+; Rosa26 N1ICD /+) and loss-of-function approaches (Emx2 Cre /+; Rosa26 DnMAML1 /+). Furthermore, we demonstrate that Notch over-activation in the differentiating murine cochlea ( Emx2 Cre /+; Rosa26 N1ICD /+) actively promotes a SC-specific gene expression program. Finally, we show that outer SCs –so called Deiters’ cells are selectively lost by prolonged reduction ( Emx2 Cre /+; Rosa26 DnMAML1 /+/+) or abolishment of canonical Notch signaling ( Fgfr3-iCreER; Rbpj − /Δ), indicating a critical role for Notch signaling in Deiters’ cell development.