title: Hypoxia promotes production of neural crest cells in the embryonic head.
abstract: Hypoxia is encountered in either pathological or physiological conditions, the latter of which is seen in amniote embryos prior to the commencement of a functional blood circulation. During the hypoxic stage, a large number of neural crest cells arise from the head neural tube by epithelial-to-mesenchymal transition (EMT). As EMT-like cancer dissemination can be promoted by hypoxia, we investigated whether hypoxia contributes to embryonic EMT. Using chick embryos, we show that the hypoxic cellular response, mediated by hypoxia-inducible factor (HIF)-1α, is required to produce a sufficient number of neural crest cells. Among the genes that are involved in neural crest cell development, some genes are more sensitive to hypoxia than others, demonstrating that the effect of hypoxia is gene specific. Once blood circulation becomes fully functional, the embryonic head no longer produces neural crest cells in vivo, despite the capability to do so in a hypoxia-mimicking condition in vitro, suggesting that the oxygen supply helps to stop emigration of neural crest cells in the head. These results highlight the importance of hypoxia in normal embryonic development.
authors.affiliation: School of Medicine, University College Dublin, Dublin 4, Ireland.
authors.forename: Deirdre
authors.initials: D
authors.lastname: Scully
authors.affiliation: School of Medicine, University College Dublin, Dublin 4, Ireland.
authors.forename: Eleanor
authors.initials: E
authors.lastname: Keane
authors.affiliation: Faculty of Health Sciences, University of Bristol, Bristol BS2 8EJ, UK.
authors.forename: Emily
authors.initials: E
authors.lastname: Batt
authors.affiliation: School of Medicine, University College Dublin, Dublin 4, Ireland.
authors.forename: Priyadarssini
authors.initials: P
authors.lastname: Karunakaran
authors.affiliation: School of Medicine, University College Dublin, Dublin 4, Ireland.
authors.forename: Debra F
authors.initials: DF
authors.lastname: Higgins
authors.affiliation: School of Medicine, University College Dublin, Dublin 4, Ireland Faculty of Health Sciences, University of Bristol, Bristol BS2 8EJ, UK nobue.itasaki@bristol.ac.uk.
authors.forename: Nobue
authors.initials: N
authors.lastname: Itasaki
mesh_terms: D000600:Amino Acids, Dicarboxylic / Q000494:pharmacology; D000818:Animals; D030161:Avian Proteins / Q000378:metabolism; D015415:Biomarkers / Q000378:metabolism; D015687:Cell Hypoxia / Q000187:drug effects; D019070:Cell Lineage / Q000187:drug effects; D002465:Cell Movement / Q000187:drug effects; D000066670:Cell Plasticity / Q000187:drug effects; D002478:Cells, Cultured; D002642:Chick Embryo; D058750:Epithelial-Mesenchymal Transition / Q000187:drug effects; D006257:Head / Q000196:embryology*; D018496:Hyperoxia / Q000378:metabolism; D051795:Hypoxia-Inducible Factor 1, alpha Subunit / Q000378:metabolism; D009432:Neural Crest / Q000166:cytology*; D054259:Neural Tube / Q000187:drug effects / Q000378:metabolism; D013194:Staining and Labeling
chemical_list: D000600:Amino Acids, Dicarboxylic; D030161:Avian Proteins; D015415:Biomarkers; D051795:Hypoxia-Inducible Factor 1, alpha Subunit; C040947:oxalylglycine
keywords: Chick embryo; HIF-1α; Hypoxia; Neural crest cells