Islet‐1 expression in the developing chicken inner ear
- 22 July 2004
- journal article
- research article
- Published by Wiley in Journal of Comparative Neurology
- Vol. 477 (1), 1-10
- https://doi.org/10.1002/cne.20190
Abstract
The cell types of the inner ear originate from the otic placode, a thickened layer of ectoderm adjacent to the developing hindbrain. The placode invaginates and forms the otic pit, which pinches off as a small vesicle called the otocyst. Presumptive cochleovestibular neurons delaminate from the anterior ventral part of the otocyst and form the cochleovestibular ganglion of the inner ear. Here we show that the LIM/homeodomain protein islet‐1 is expressed in cells of the ventral part of the otic placode and that this ventral expression is maintained at the otic pit and the otocyst stages. Auditory and vestibular neurons originate from this islet‐1‐positive zone of the otocyst, and these neurons maintain islet‐1 expression until adulthood. We also demonstrate that islet‐1 becomes up‐regulated in the presumptive sensory epithelia of the inner ear in regions that are defined by the expression domains of BMP4. The up‐regulation of islet‐1 in developing inner ear hair and supporting cells is accompanied by down‐regulation of Pax‐2 in these cell types. Islet‐1 expression in hair and supporting cells persists until early postnatal stages, when the transcriptional regulator is down‐regulated in hair cells. Our data is consistent with a role for islet‐1 in differentiating inner ear neurons and sensory epithelia cells, perhaps in the specification of cellular subtypes in conjunction with other LIM/homeodomain proteins. J. Comp. Neurol. 477:1–10, 2004.Keywords
This publication has 42 references indexed in Scilit:
- Development and evolution of inner ear sensory epithelia and their innervationJournal of Neurobiology, 2002
- Delayed Inner Ear Maturation and Neuronal Loss in PostnatalIgf-1-Deficient MiceJournal of Neuroscience, 2001
- Molecular genetics of pattern formation in the inner ear: Do compartment boundaries play a role?Proceedings of the National Academy of Sciences of the United States of America, 2000
- Sensory organ generation in the chicken inner ear: Contributions ofBone morphogenetic protein 4, Serrate1, andLunatic fringeJournal of Comparative Neurology, 2000
- Ectopic Noggin Blocks Sensory and Nonsensory Organ Morphogenesis in the Chicken Inner EarDevelopmental Biology, 1999
- Cell fate specification in the inner earCurrent Opinion in Neurobiology, 1996
- Standard atlas of the gross anatomy of the developing inner ear of the chickenJournal of Comparative Neurology, 1996
- Brn-3.0 expression identifies early post-mitotic CNS neurons and sensory neural precursorsMechanisms of Development, 1995
- Sonic hedgehog induces the differentiation of ventral forebrain neurons: A common signal for ventral patterning within the neural tubeCell, 1995
- Early Stages of Motor Neuron Differentiation Revealed by Expression of Homeobox Gene Islet-1Science, 1992