title: Conditional deletion of N-Myc disrupts neurosensory and non-sensory development of the ear.
abstract: Ear development requires interactions of transcription factors for proliferation and differentiation. The proto-oncogene N-Myc is a member of the Myc family that regulates proliferation. To investigate the function of N-Myc, we conditionally knocked out N-Myc in the ear using Tg(Pax2-Cre) and Foxg1(KiCre). N-Myc CKOs had reduced growth of the ear, abnormal morphology including fused sensory epithelia, disrupted histology, and disorganized neuronal innervation. Using Thin-Sheet Laser Imaging Microscopy (TSLIM), 3D reconstruction and quantification of the cochlea revealed a greater than 50% size reduction. Immunochemistry and in situ hybridization showed a gravistatic organ-cochlear fusion and a "circularized" apex with no clear inner and outer hair cells. Furthermore, the abnormally developed cochlea had cross innervation from the vestibular ganglion near the basal tip. These findings are put in the context of the possible functional relationship of N-Myc with a number of other cell proliferative and fate determining genes during ear development.
authors: Department of Biology, University of Iowa, Iowa City, Iowa, USA.
authors: Benjamin
authors: B
authors: Kopecky
authors: Peter
authors: P
authors: Santi
authors: Shane
authors: S
authors: Johnson
authors: Heather
authors: H
authors: Schmitz
authors: Bernd
authors: B
authors: Fritzsch
mesh_terms: D000818:Animals; D002454:Cell Differentiation / Q000235:genetics / Q000502:physiology; D003198:Computer Simulation; D004423:Ear / Q000033:anatomy & histology / Q000196:embryology* / Q000254:growth & development; D004848:Epithelium / Q000196:embryology* / Q000378:metabolism; D017353:Gene Deletion; D018507:Gene Expression Regulation, Developmental; D018014:Gene Transfer Techniques; D016259:Genes, myc / Q000235:genetics* / Q000502:physiology; D051379:Mice; D018345:Mice, Knockout; D009928:Organ Specificity / Q000235:genetics; D011984:Sensory Receptor Cells / Q000378:metabolism / Q000502:physiology*