title: Aortic arch and pharyngeal phenotype in the absence of BMP-dependent neural crest in the mouse.
abstract: Neural crest cells are essential for proper development of a variety of tissues and structures, including peripheral and autonomic nervous systems, facial skeleton, aortic arches and pharyngeal glands like the thymus and parathyroids. Previous work has shown that bone morphogenic protein (BMP) signalling is required for the production of migratory neural crest cells that contribute to the neurogenic and skeletogenic lineages. We show here that BMP-dependent neural crest cells are also required for development of the embryonic aortic arches and pharynx-derived glands. Blocking formation or migration of this crest cell population from the caudal hindbrain resulted in strong phenotypes in the cardiac outflow tract and the thymus. Thymic aplasia or hypoplasia occurs despite uncompromised gene induction in the pharyngeal endoderm. In addition, when hypoplastic thymic tissue is found, it is ectopically located, but functional in thymopoiesis. Our data indicate that thymic phenotypes produced by neural crest deficits result from aberrant formation of pharyngeal pouches and impaired migration of thymic primordia because the mesenchymal content in the branchial arches is below a threshold level.
authors.affiliation: Department of Developmental Biology, Max-Planck Institute of Immunobiology, Freiburg, Germany.
authors.forename: Sabine
authors.initials: S
authors.lastname: Ohnemus
authors.forename: Benoît
authors.initials: B
authors.lastname: Kanzler
authors.forename: Loydie A
authors.initials: LA
authors.lastname: Jerome-Majewska
authors.forename: Virginia E
authors.initials: VE
authors.lastname: Papaioannou
authors.forename: Thomas
authors.initials: T
authors.lastname: Boehm
authors.forename: Moisés
authors.initials: M
authors.lastname: Mallo
mesh_terms: D000818:Animals; D030801:Animals, Genetically Modified; D001013:Aorta, Thoracic / Q000196:embryology*; D019485:Bone Morphogenetic Proteins / Q000378:metabolism*; D019070:Cell Lineage; D002465:Cell Movement; D018076:DNA, Complementary / Q000378:metabolism; D004062:DiGeorge Syndrome / Q000235:genetics; D015536:Down-Regulation; D015723:Gene Library; D006801:Humans; D017403:In Situ Hybridization; D051379:Mice; D008810:Mice, Inbred C57BL; D008822:Mice, Transgenic; D008954:Models, Biological; D009154:Mutation; D009432:Neural Crest / Q000196:embryology* / Q000378:metabolism; D010641:Phenotype; D015398:Signal Transduction; D013950:Thymus Gland / Q000196:embryology / Q000378:metabolism; D013997:Time Factors; D014981:Xenopus
chemical_list: D019485:Bone Morphogenetic Proteins; D018076:DNA, Complementary