title: Fate map of the chicken otic placode.
abstract: The inner ear is an intricate three-dimensional sensory organ that arises from a flat, thickened portion of the ectoderm termed the otic placode. There is evidence that the ontogenetic steps involved in the progressive specification of the highly specialized inner ear of vertebrates involve the concerted actions of diverse patterning signals that originate from nearby tissues, providing positional identity and instructive context. The topology of the prospective inner ear portions at placode stages when such patterning begins has remained largely unknown. The chick-quail model was used to perform a comprehensive fate mapping study of the chick otic placode, shedding light on the precise topological position of each presumptive inner ear component relative to the dorsoventral and anteroposterior axes of the otic placode and, implicitly, to the possible sources of inducing signals. The findings reveal the existence of three dorsoventrally arranged anteroposterior domains from which the endolymphatic system, the maculae and basilar papilla, and the cristae develop. This study provides new bases for the interpretation of earlier and future descriptive and experimental studies that aim to understand the molecular genetic mechanisms involved in otic placode patterning.
authors.affiliation: Department of Cell Biology, Faculty of Science, University of Extremadura, 06071 Badajoz, Spain.
authors.forename: Luis Óscar
authors.initials: LÓ
authors.lastname: Sánchez-Guardado
authors.affiliation: Department of Human Anatomy and Psychobiology, School of Medicine, University of Murcia, 30003 Murcia, Spain.
authors.forename: Luis
authors.initials: L
authors.lastname: Puelles
authors.affiliation: Department of Cell Biology, Faculty of Science, University of Extremadura, 06071 Badajoz, Spain mhidalgo@unex.es.
authors.forename: Matías
authors.initials: M
authors.lastname: Hidalgo-Sánchez
mesh_terms: D000818:Animals; D019521:Body Patterning / Q000502:physiology*; D019070:Cell Lineage; D002642:Chick Embryo; D002645:Chickens; D007758:Ear, Inner / Q000196:embryology* / Q000502:physiology*; D004475:Ectoderm / Q000378:metabolism / Q000502:physiology; D018507:Gene Expression Regulation, Developmental; D011784:Quail; D015398:Signal Transduction; D014157:Transcription Factors / Q000235:genetics
chemical_list: D014157:Transcription Factors
keywords: Cell lineage; Compartment; Cristae; Endolymphatic system; Maculae; Morphogenesis; Otic specification; Semicircular canals; Sensory patch; Tegmentum vasculosum