title: Role of Phox2b and Mash1 in the generation of the vestibular efferent nucleus.
abstract: The inner ear (vestibular and cochlear) efferent neurons are a group of atypical motor-like hindbrain neurons which innervate inner ear hair cells and their sensory afferents. They are born in the fourth rhombomere, in close association with facial branchial motor neurons, from which they subsequently part through a specific migration route. Here, we demonstrate that the inner ear efferents depend on Phox2b for their differentiation, behaving in that respect like hindbrain visceral and branchial motor neurons. We also show that the vestibular efferent nucleus is no longer present at its usual site in mice inactivated for the bHLH transcription factor Mash 1. The concomitant appearance of an ectopic branchial-like nucleus at the location where both inner ear efferents and facial branchial motor neurons are born suggests that Mash1 is required for the migration of a subpopulation of rhombomere 4-derived efferents.
authors.affiliation: CNRS UMR 6156, NMDA-IBDM, Case 907 Parc Scientifique de Luminy, 13288, Marseille Cedex 9, France.
authors.forename: M-C
authors.initials: MC
authors.lastname: Tiveron
authors.forename: A
authors.initials: A
authors.lastname: Pattyn
authors.forename: M-R
authors.initials: MR
authors.lastname: Hirsch
authors.forename: J-F
authors.initials: JF
authors.lastname: Brunet
mesh_terms: D000818:Animals; D051792:Basic Helix-Loop-Helix Proteins; D002454:Cell Differentiation; D002642:Chick Embryo; D004268:DNA-Binding Proteins / Q000502:physiology*; D018507:Gene Expression Regulation, Developmental; D018398:Homeodomain Proteins / Q000235:genetics / Q000502:physiology*; D051379:Mice; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout; D008817:Mice, Mutant Strains; D009154:Mutation; D009419:Nerve Tissue Proteins / Q000235:genetics / Q000502:physiology*; D009476:Neurons, Efferent / Q000166:cytology / Q000502:physiology*; D014157:Transcription Factors / Q000235:genetics / Q000502:physiology*; D014726:Vestibular Nuclei / Q000166:cytology / Q000196:embryology / Q000502:physiology*
chemical_list: D051792:Basic Helix-Loop-Helix Proteins; D004268:DNA-Binding Proteins; D018398:Homeodomain Proteins; D009419:Nerve Tissue Proteins; D014157:Transcription Factors; C499317:Ascl1 protein, mouse; C109220:NBPhox protein