Related Experiment Video
Updated: Aug 5, 2026
11:27
Selective Tracing of Auditory Fibers in the Avian Embryonic Vestibulocochlear Nerve
Published on: March 18, 2013
The Notch ligand Jagged1 is required for inner ear sensory development
A E Kiernan1, N Ahituv, H Fuchs
1Medical Research Council Institute of Hearing Research, University Park, Nottingham NG7 2RD, United Kingdom.
Summary
Jagged1 (Jag1) mutations disrupt inner ear development, suggesting Notch signaling specifies sensory regions early on. This challenges the idea that Notch signaling solely mediates lateral inhibition for sensory cell arrangement.
Area of Science:
- Developmental biology
- Neuroscience
- Genetics
Background:
- Mammalian inner ear has six sensory regions for hearing and balance.
- Sensory regions contain hair cells and supporting cells in a mosaic pattern.
- Notch signaling is proposed to mediate lateral inhibition for this mosaic.
Purpose of the Study:
- Investigate the role of Jagged1 (Jag1) in inner ear sensory region specification.
- Determine if Notch signaling has a role beyond lateral inhibition in the inner ear.
Main Methods:
- Studied the dominant mouse mutant headturner (Htu).
- Analyzed the Jag1 gene for mutations in Htu mutants.
- Examined the development of sensory structures in Htu/+ mutants.
Main Results:
- Htu mutation is a missense mutation in the Jag1 gene.
- Htu/+ mutants show missing posterior and sometimes anterior ampullae.
- Htu/+ mutants have reduced outer hair cells in the organ of Corti.
Conclusions:
- Jag1 mutations impact inner ear sensory development.
- Data suggest Notch signaling specifies sensory regions early in development.
- This indicates a role for Notch signaling prior to lateral inhibition.
Related Concept Videos
01:30Neurulation
Neurulation is the embryological process which forms the precursors of the central nervous system and occurs after gastrulation has established the three primary cell layers of the embryo: ectoderm, mesoderm, and endoderm. In humans, the majority of this system is formed via primary neurulation, in which the central portion of the ectoderm—originally appearing as a flat sheet of cells—folds upwards and inwards, sealing off to form a hollow neural tube. As development proceeds, the anterior...
03:14Notch Signaling Pathway
The Notch signaling pathway is a major intracellular signaling pathway that is highly conserved over a broad spectrum of metazoan species. It stands unique from other intracellular signaling mechanisms in animals because notch protein itself acts as the receptor as well as the primary signaling molecule.
The Notch gene came into the limelight in 1914 after the discovery that its mutation in Drosophila melanogaster leads to a serrated (or "notched") wing margin phenotype. It was not until 1985...
The Notch gene came into the limelight in 1914 after the discovery that its mutation in Drosophila melanogaster leads to a serrated (or "notched") wing margin phenotype. It was not until 1985...
02:33Hedgehog Signaling Pathway
The Hedgehog gene (Hh) was first discovered due to its control of the growth of disorganized, hair-like bristles phenotype in Drosophila, much like hedgehog spines. Hh plays a crucial role in the development of organs and the maintenance of homeostasis in both invertebrates and vertebrates. However, while Drosophila has only one Hh protein, mammals have multiple functional Hedgehog proteins - Sonic (Shh), Desert (Dhh), and Indian Hedgehog (Ihh). All of these homologous proteins have adapted to...
03:14Notch Signaling Pathway
The Notch signaling pathway is a major intracellular signaling pathway that is highly conserved over a broad spectrum of metazoan species. It stands unique from other intracellular signaling mechanisms in animals because notch protein itself acts as the receptor as well as the primary signaling molecule.
The Notch gene came into the limelight in 1914 after the discovery that its mutation in Drosophila melanogaster leads to a serrated (or "notched") wing margin phenotype. It was not until 1985...
The Notch gene came into the limelight in 1914 after the discovery that its mutation in Drosophila melanogaster leads to a serrated (or "notched") wing margin phenotype. It was not until 1985...
02:33Hedgehog Signaling Pathway
The Hedgehog gene (Hh) was first discovered due to its control of the growth of disorganized, hair-like bristles phenotype in Drosophila, much like hedgehog spines. Hh plays a crucial role in the development of organs and the maintenance of homeostasis in both invertebrates and vertebrates. However, while Drosophila has only one Hh protein, mammals have multiple functional Hedgehog proteins - Sonic (Shh), Desert (Dhh), and Indian Hedgehog (Ihh). All of these homologous proteins have adapted to...
01:12Role Of Notch Signalling In Intestinal Stem Cell Renewal
Notch signaling was first discovered in Drosophila melanogaster, where it is involved in cell lineage differentiation. Notch signaling regulates the maintenance and differentiation of intestinal stem cells or ISCs by controlling the expression of atonal homolog 1 or Atoh1. Atoh1 directs cells to differentiate into secretory cells.
Direct cell-to-cell contact is needed for the activation of Notch signaling. The signal is initiated when a notch ligand binds to a receptor on an adjacent cell, also...
Direct cell-to-cell contact is needed for the activation of Notch signaling. The signal is initiated when a notch ligand binds to a receptor on an adjacent cell, also...