title: Sox3 expression defines a common primordium for the epibranchial placodes in chick.
abstract: The epibranchial placodes are ectodermal thickenings that generate sensory neurons of the distal ganglia of the branchial nerves. Although significant advances in our understanding of neurogenesis from the placodes have recently been made, the events prior to the onset of neurogenesis remain unclear. We found that chick Sox3 (cSox3) shows a highly dynamic pattern of expression before becoming confined to the final placodes: one pre-otic (geniculate) and three post-otic (one petrosal and two nodose) placodes. A fate-mapping study using lipophilic dyes revealed that all post-otic placodes arise within a single broad cSox3-positive domain, where cSox3 expression and epithelial thickness will be retained only in much smaller final neurogenic placodes. The data presented here suggest that post-otic placodes are remnants of a common primordium defined as a discrete domain of cSox3 expression.
authors.affiliation: Nottingham Children's Brain Tumour Research Centre, University of Nottingham, Nottingham, NG7 2UH, United Kingdom.
authors.forename: Y
authors.initials: Y
authors.lastname: Ishii
authors.forename: M
authors.initials: M
authors.lastname: Abu-Elmagd
authors.forename: P J
authors.initials: PJ
authors.lastname: Scotting
mesh_terms: D000818:Animals; D001934:Branchial Region / Q000166:cytology / Q000196:embryology* / Q000378:metabolism*; D019070:Cell Lineage; D002465:Cell Movement; D002642:Chick Embryo; D004268:DNA-Binding Proteins / Q000378:metabolism*; D004475:Ectoderm / Q000166:cytology / Q000378:metabolism; D004848:Epithelium / Q000196:embryology / Q000378:metabolism; D015870:Gene Expression; D006609:High Mobility Group Proteins / Q000378:metabolism*; D017403:In Situ Hybridization; D009024:Morphogenesis; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D055748:SOXB1 Transcription Factors; D013997:Time Factors; D014157:Transcription Factors
chemical_list: D004268:DNA-Binding Proteins; D006609:High Mobility Group Proteins; D012333:RNA, Messenger; D055748:SOXB1 Transcription Factors; D014157:Transcription Factors