title: Deletion of the endothelin-A receptor gene within the developing mandible.
abstract: Signaling from the endothelin-A (Ednra) receptor is responsible for initiating multiple signaling pathways within neural crest cells (NCCs). Loss of this initiation is presumably the basis for the craniofacial defects observed in Ednra-/- embryos. However, it is not known whether continued Ednra signaling in NCC derivatives is required for subsequent development of the lower jaw. To address this question, mice containing loxP recombination sequences flanking a portion of the Ednra gene were bred with transgenic mice that express Cre recombinase under control of a Dlx5/6 enhancer element. We find that while Ednra gene inactivation within the mandibular arch of these Ednra conditional knockout embryos is detectable by embryonic day (E) 10.5, mandibular arch-specific gene expression is normal, as is overall mandible development. These results suggest that while Ednra receptor signaling is crucial for early NCC patterning, subsequent Ednra signaling is not essential for mandible bone development.
authors.affiliation: Department of Molecular, Cellular and Craniofacial Biology and the Birth Defects Center, University of Louisville, Louisville, KY, 40292, USA.
authors.forename: Louis-Bruno
authors.initials: LB
authors.lastname: Ruest
authors.forename: Rafal
authors.initials: R
authors.lastname: Kedzierski
authors.forename: Masashi
authors.initials: M
authors.lastname: Yanagisawa
authors.forename: David E
authors.initials: DE
authors.lastname: Clouthier
mesh_terms: D000818:Animals; D047108:Embryonic Development / Q000235:genetics; D005260:Female; D017353:Gene Deletion; D018507:Gene Expression Regulation, Developmental; D005865:Gestational Age; D017403:In Situ Hybridization; D019426:Integrases / Q000235:genetics / Q000378:metabolism; D008297:Male; D008334:Mandible / Q000196:embryology* / Q000378:metabolism; D051379:Mice; D008815:Mice, Inbred Strains; D018345:Mice, Knockout; D044022:Receptor, Endothelin A / Q000172:deficiency / Q000235:genetics / Q000378:metabolism; D015398:Signal Transduction
chemical_list: D044022:Receptor, Endothelin A; C045073:Cre recombinase; D019426:Integrases