Development 129, 2495-2505 (2002) 2495 Printed in Great Britain © The Company of Biologists Limited 2002 DEV1807 The role of Math1 in inner ear development: Uncoupling the establishment of the sensory primordium from hair cell fate determination Ping Chen1,*, Jane E. Johnson2, Huda Y. Zoghbi3 and Neil Segil1,4,* 1Gonda Department of Cell and Molecular Biology, House Ear Institute, Los Angeles, CA 90057, USA 2Center for Basic Neuroscience, University of Texas Southwestern Medical Center, 5323 Harry Hines Blvd, Dallas, TX 75390, USA 3Department of Molecular and Human Genetics, Howard Hughes Medical Institute, Baylor College of Medicine, Houston, TX 77030, USA 4Department of Cell and Neurobiology, University of Southern California Medical School, Los Angeles, CA 90033, USA *Authors for correspondence (e-mail:
[email protected] and
[email protected]) Accepted 5 March 2002 SUMMARY During embryonic development of the inner ear, the anlage. The expression of Math1 is limited to a sensory primordium that gives rise to the organ of Corti subpopulation of cells within the sensory primordium that from within the cochlear epithelium is patterned into a appear to differentiate exclusively into hair cells as the stereotyped array of inner and outer sensory hair cells sensory epithelium matures and elongates through a separated from each other by non-sensory supporting cells. process that probably involves radial intercalation of cells. Math1, a close homolog of the Drosophila proneural gene Furthermore, mutation of Math1 does not affect the atonal, has been found to be both necessary and sufficient establishment of this postmitotic sensory primordium, even for the production of hair cells in the mouse inner ear.