Rbpj regulates development of prosensory cells in the mammalian inner ear

► We deleted Rbpj gene in embryonic mice inner ears to study roles of Notch signaling. ► Nearly all mechanosensory hair cells are absent in inner ear specific Rbpj mutants. ► However, markers of the prosensory domain are still expressed. ► Further analysis suggests multiple roles of Notch signaling in inner ear development. ► It controls the differentiation timing and maintains a stem/progenitor cell stage.