title: Cell communication with the neural plate is required for induction of neural markers by BMP inhibition: evidence for homeogenetic induction and implications for Xenopus animal cap and chick explant assays.
abstract: In Xenopus, the animal cap is very sensitive to BMP antagonists, which result in neuralization. In chick, however, only cells at the border of the neural plate can be neuralized by BMP inhibition. Here we compare the two systems. BMP antagonists can induce neural plate border markers in both ventral Xenopus epidermis and non-neural chick epiblast. However, BMP antagonism can only neuralize ectodermal cells when the BMP-inhibited cells form a continuous trail connecting them to the neural plate or its border, suggesting that homeogenetic neuralizing factors can only travel between BMP-inhibited cells. Xenopus animal cap explants contain cells fated to contribute to the neural plate border and even to the anterior neural plate, explaining why they are so easily neuralized by BMP-inhibition. Furthermore, chick explants isolated from embryonic epiblast behave like Xenopus animal caps and express border markers. We propose that the animal cap assay in Xenopus and explant assays in the chick are unsuitable for studying instructive signals in neural induction.
authors.affiliation: Department of Cell and Developmental Biology, University College London, Gower Street (Anatomy Building), London WC1E 6BT, UK. claudia.linker@cancer.org.uk
authors.forename: Claudia
authors.initials: C
authors.lastname: Linker
authors.forename: Irene
authors.initials: I
authors.lastname: De Almeida
authors.forename: Costis
authors.initials: C
authors.lastname: Papanayotou
authors.forename: Matthew
authors.initials: M
authors.lastname: Stower
authors.forename: Virginie
authors.initials: V
authors.lastname: Sabado
authors.forename: Ehsan
authors.initials: E
authors.lastname: Ghorani
authors.forename: Andrea
authors.initials: A
authors.lastname: Streit
authors.forename: Roberto
authors.initials: R
authors.lastname: Mayor
authors.forename: Claudio D
authors.initials: CD
authors.lastname: Stern
mesh_terms: D000818:Animals; D001681:Biological Assay / Q000379:methods; D015415:Biomarkers / Q000378:metabolism*; D019485:Bone Morphogenetic Proteins / Q000037:antagonists & inhibitors* / Q000235:genetics / Q000378:metabolism; D002450:Cell Communication / Q000502:physiology*; D002642:Chick Embryo; D004627:Embryonic Induction / Q000502:physiology*; D050989:GATA2 Transcription Factor / Q000235:genetics / Q000378:metabolism; D050990:GATA3 Transcription Factor / Q000235:genetics / Q000378:metabolism; D018507:Gene Expression Regulation, Developmental; D054258:Neural Plate / Q000166:cytology / Q000502:physiology*; D019737:Transplants; D029867:Xenopus Proteins / Q000235:genetics / Q000378:metabolism; D014982:Xenopus laevis / Q000033:anatomy & histology / Q000196:embryology
chemical_list: D015415:Biomarkers; D019485:Bone Morphogenetic Proteins; D050989:GATA2 Transcription Factor; D050990:GATA3 Transcription Factor; D029867:Xenopus Proteins