Notch signalling pathway mediates hair cell development in mammalian cochlea

Nat Genet. 1999 Mar;21(3):289-92. doi: 10.1038/6804.


The mammalian cochlea contains an invariant mosaic of sensory hair cells and non-sensory supporting cells reminiscent of invertebrate structures such as the compound eye in Drosophila melanogaster. The sensory epithelium in the mammalian cochlea (the organ of Corti) contains four rows of mechanosensory hair cells: a single row of inner hair cells and three rows of outer hair cells. Each hair cell is separated from the next by an interceding supporting cell, forming an invariant and alternating mosaic that extends the length of the cochlear duct. Previous results suggest that determination of cell fates in the cochlear mosaic occurs via inhibitory interactions between adjacent progenitor cells (lateral inhibition). Cells populating the cochlear epithelium appear to constitute a developmental equivalence group in which developing hair cells suppress differentiation in their immediate neighbours through lateral inhibition. These interactions may be mediated through the Notch signalling pathway, a molecular mechanism that is involved in the determination of a variety of cell fates. Here we show that genes encoding the receptor protein Notch1 and its ligand, Jagged 2, are expressed in alternating cell types in the developing sensory epithelium. In addition, genetic deletion of Jag2 results in a significant increase in sensory hair cells, presumably as a result of a decrease in Notch activation. These results provide direct evidence for Notch-mediated lateral inhibition in a mammalian system and support a role for Notch in the development of the cochlear mosaic.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Animals
  • Calcium-Binding Proteins
  • Carrier Proteins / genetics
  • Carrier Proteins / metabolism
  • Cell Differentiation / genetics
  • Cochlea / cytology
  • Cochlea / embryology
  • Cochlea / growth & development*
  • Drosophila Proteins
  • Embryonic Induction / genetics
  • Female
  • Gene Expression Regulation, Developmental*
  • Hair Cells, Auditory, Outer / growth & development*
  • Hair Cells, Auditory, Outer / pathology
  • Intercellular Signaling Peptides and Proteins
  • Jagged-1 Protein
  • Jagged-2 Protein
  • Male
  • Mammals
  • Membrane Proteins / genetics*
  • Membrane Proteins / metabolism*
  • Mice
  • Mice, Mutant Strains
  • Morphogenesis / genetics
  • Mutation
  • Organ of Corti / embryology
  • Organ of Corti / physiology
  • Pregnancy
  • Proteins / genetics
  • Proteins / metabolism
  • Receptor, Notch1
  • Receptors, Cell Surface*
  • Serrate-Jagged Proteins
  • Signal Transduction
  • Transcription Factors*


  • Calcium-Binding Proteins
  • Carrier Proteins
  • Drosophila Proteins
  • Intercellular Signaling Peptides and Proteins
  • Jag1 protein, mouse
  • Jag2 protein, mouse
  • Jagged-1 Protein
  • Jagged-2 Protein
  • Membrane Proteins
  • Notch1 protein, mouse
  • Proteins
  • Receptor, Notch1
  • Receptors, Cell Surface
  • Ser protein, Drosophila
  • Serrate-Jagged Proteins
  • Transcription Factors

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