First published online March 9, 2006
Development 133, 702e (2006)
© The Company of Biologists Limited
Hear hear: induction and inhibition Notched up
During development, Notch activation in one cell can inhibit its ability to
make Notch ligands and so activate Notch in its neighbours. This `lateral
inhibition' produces mosaics of cells with different fates. However, sometimes
Notch activation activates Notch ligand expression in the given cell, thereby
driving neighbouring cells into a similar state (lateral induction). Now,
Julian Lewis and colleagues report that, during mouse inner ear development,
the Notch pathway first uses the Jagged1 (Jag1) ligand to induce prosensory
patch formation - from which the sensory cells of the ear develop - and later
uses Delta1 (Dll1) to control the formation of different sensory cell types
through lateral inhibition (see p.
1277). They show that
cochlear hair cells are produced early and in excess when Dll1 is
conditionally deleted in the mouse ear, indicating a failure of lateral
inhibition. By contrast, conditional Jag1 knockouts have a severe
deficit of sensory tissue, indicating that prosensory cell induction has
failed. These results provide new insights into inner ear development and the
distinct developmental roles of different Notch ligands.
Related articles in Development:
- Notch ligands with contrasting functions: Jagged1 and Delta1 in the mouse inner ear
- Rachael Brooker, Katsuto Hozumi, and Julian Lewis
Development 2006 133: 1277-1286.
[Abstract]
[Full Text]
