title: A conserved role for non-neural ectoderm cells in early neural development.
abstract: During the early steps of head development, ectodermal patterning leads to the emergence of distinct non-neural and neural progenitor cells. The induction of the preplacodal ectoderm and the neural crest depends on well-studied signalling interactions between the non-neural ectoderm fated to become epidermis and the prospective neural plate. By contrast, the involvement of the non-neural ectoderm in the morphogenetic events leading to the development and patterning of the central nervous system has been studied less extensively. Here, we show that the removal of the rostral non-neural ectoderm abutting the prospective neural plate at late gastrulation stage leads, in mouse and chick embryos, to morphological defects in forebrain and craniofacial tissues. In particular, this ablation compromises the development of the telencephalon without affecting that of the diencephalon. Further investigations of ablated mouse embryos established that signalling centres crucial for forebrain regionalization, namely the axial mesendoderm and the anterior neural ridge, form normally. Moreover, changes in cell death or cell proliferation could not explain the specific loss of telencephalic tissue. Finally, we provide evidence that the removal of rostral tissues triggers misregulation of the BMP, WNT and FGF signalling pathways that may affect telencephalon development. This study opens new perspectives on the role of the neural/non-neural interface and reveals its functional relevance across higher vertebrates.
authors.affiliation: Université Paris Diderot, Sorbonne Paris Cité, Institut Jacques Monod, UMR7592 CNRS, Paris F-75013, France.
authors.forename: Marieke
authors.initials: M
authors.lastname: Cajal
authors.affiliation: Institut de Neurobiologie, Laboratoire Neurobiologie et Développement, CNRS-UPR3294, avenue de la Terrasse, Gif-sur-Yvette 91198, France.
authors.forename: Sophie E
authors.initials: SE
authors.lastname: Creuzet
authors.affiliation: Université Paris Diderot, Sorbonne Paris Cité, Institut Jacques Monod, UMR7592 CNRS, Paris F-75013, France.
authors.forename: Costis
authors.initials: C
authors.lastname: Papanayotou
authors.affiliation: Université Paris Diderot, Sorbonne Paris Cité, Institut Jacques Monod, UMR7592 CNRS, Paris F-75013, France.
authors.forename: Délara
authors.initials: D
authors.lastname: Sabéran-Djoneidi
authors.affiliation: Department of Anatomy and Embryology, Leiden University Medical Centre, Leiden 2333 ZC, The Netherlands.
authors.forename: Susana M
authors.initials: SM
authors.lastname: Chuva de Sousa Lopes
authors.affiliation: Laboratory of Developmental Signaling, VIB Center for the Biology of Disease, and KU Leuven, Department for Human Genetics, Leuven 3000, Belgium.
authors.forename: An
authors.initials: A
authors.lastname: Zwijsen
authors.affiliation: Université Paris Diderot, Sorbonne Paris Cité, Institut Jacques Monod, UMR7592 CNRS, Paris F-75013, France.
authors.forename: Jérôme
authors.initials: J
authors.lastname: Collignon
authors.affiliation: Université Paris Diderot, Sorbonne Paris Cité, Institut Jacques Monod, UMR7592 CNRS, Paris F-75013, France camus.anne@ijm.univ-paris-diderot.fr.
authors.forename: Anne
authors.initials: A
authors.lastname: Camus
mesh_terms: D000818:Animals; D017209:Apoptosis / Q000235:genetics / Q000502:physiology; D019521:Body Patterning / Q000235:genetics / Q000502:physiology; D002642:Chick Embryo; D004475:Ectoderm / Q000196:embryology* / Q000378:metabolism; D005260:Female; D018507:Gene Expression Regulation, Developmental / Q000235:genetics / Q000502:physiology; D051379:Mice; D009432:Neural Crest / Q000196:embryology / Q000378:metabolism; D055495:Neurogenesis / Q000235:genetics / Q000502:physiology; D011247:Pregnancy; D016548:Prosencephalon / Q000196:embryology / Q000378:metabolism; D013687:Telencephalon / Q000196:embryology / Q000378:metabolism
keywords: Apoptosis; Chick; Embryo; Forebrain patterning; Mouse; Signalling centre; Telencephalon; Vertebrates