title: Clonal and molecular analysis of the prospective anterior neural boundary in the mouse embryo.
abstract: In the mouse embryo the anterior ectoderm undergoes extensive growth and morphogenesis to form the forebrain and cephalic non-neural ectoderm. We traced descendants of single ectoderm cells to study cell fate choice and cell behaviour at late gastrulation. In addition, we provide a comprehensive spatiotemporal atlas of anterior gene expression at stages crucial for anterior ectoderm regionalisation and neural plate formation. Our results show that, at late gastrulation stage, expression patterns of anterior ectoderm genes overlap significantly and correlate with areas of distinct prospective fates but do not define lineages. The fate map delineates a rostral limit to forebrain contribution. However, no early subdivision of the presumptive forebrain territory can be detected. Lineage analysis at single-cell resolution revealed that precursors of the anterior neural ridge (ANR), a signalling centre involved in forebrain development and patterning, are clonally related to neural ectoderm. The prospective ANR and the forebrain neuroectoderm arise from cells scattered within the same broad area of anterior ectoderm. This study establishes that although the segregation between non-neural and neural precursors in the anterior midline ectoderm is not complete at late gastrulation stage, this tissue already harbours elements of regionalisation that prefigure the later organisation of the head.
authors.affiliation: Université Paris Diderot, Sorbonne Paris Cité, Institut Jacques Monod, UMR7592 CNRS, F-75013 Paris, France.
authors.forename: Marieke
authors.initials: M
authors.lastname: Cajal
authors.forename: Kirstie A
authors.initials: KA
authors.lastname: Lawson
authors.forename: Bill
authors.initials: B
authors.lastname: Hill
authors.forename: Anne
authors.initials: A
authors.lastname: Moreau
authors.forename: Jianguo
authors.initials: J
authors.lastname: Rao
authors.forename: Allyson
authors.initials: A
authors.lastname: Ross
authors.forename: Jérôme
authors.initials: J
authors.lastname: Collignon
authors.forename: Anne
authors.initials: A
authors.lastname: Camus
mesh_terms: D000818:Animals; D019070:Cell Lineage / Q000502:physiology*; D004475:Ectoderm / Q000166:cytology / Q000196:embryology* / Q000378:metabolism; D004622:Embryo, Mammalian / Q000196:embryology*; D054262:Gastrulation / Q000502:physiology*; D018507:Gene Expression Regulation, Developmental / Q000502:physiology*; D006652:Histological Techniques; D017403:In Situ Hybridization; D007478:Iontophoresis; D051379:Mice; D016548:Prosencephalon / Q000196:embryology*; D013194:Staining and Labeling