title: E-cadherin is required for cranial neural crest migration in Xenopus laevis.
abstract: The cranial neural crest (CNC) is a highly motile and multipotent embryonic cell population, which migrates directionally on defined routes throughout the embryo, contributing to facial structures including cartilage, bone and ganglia. Cadherin-mediated cell-cell adhesion is known to play a crucial role in the directional migration of CNC cells. However, migrating CNC co-express different cadherin subtypes, and their individual roles have yet to be fully explored. In previous studies, the expression of individual cadherin subtypes has been analysed using different methods with varying sensitivities, preventing the direct comparison of expression levels. Here, we provide the first comprehensive and comparative analysis of the expression of six cadherin superfamily members during different phases of CNC cell migration in Xenopus. By applying a quantitative RT-qPCR approach, we can determine the copy number and abundance of each expressed cadherin through different phases of CNC migration. Using this approach, we show for the first time expression of E-cadherin and XB/C-cadherin in CNC cells, adding them as two new members of cadherins co-expressed during CNC migration. Cadherin co-expression during CNC migration in Xenopus, in particular the constant expression of E-cadherin, contradicts the classical epithelial-mesenchymal transition (EMT) model postulating a switch in cadherin expression. Loss-of-function experiments further show that E-cadherin is required for proper CNC cell migration in vivo and also for cell protrusion formation in vitro. Knockdown of E-cadherin is not rescued by co-injection of other classical cadherins, pointing to a specific function of E-cadherin in mediating CNC cell migration. Finally, through reconstitution experiments with different E-cadherin deletion mutants in E-cadherin morphant embryos, we demonstrate that the extracellular domain, but not the cytoplasmic domain, of E-cadherin is sufficient to rescue CNC cell migration in vivo.
authors.affiliation: Karlsruhe Institute of Technology, Zoological Institute, Department of Cell and Developmental Biology, Germany.
authors.forename: Chaolie
authors.initials: C
authors.lastname: Huang
authors.affiliation: Karlsruhe Institute of Technology, Zoological Institute, Department of Cell and Developmental Biology, Germany; Karlsruhe Institute of Technology, Laboratory for Applications of Synchrotron Radiation, Germany.
authors.forename: Marie-Claire
authors.initials: MC
authors.lastname: Kratzer
authors.affiliation: Karlsruhe Institute of Technology, Zoological Institute, Department of Cell and Developmental Biology, Germany.
authors.forename: Doris
authors.initials: D
authors.lastname: Wedlich
authors.affiliation: Karlsruhe Institute of Technology, Zoological Institute, Department of Cell and Developmental Biology, Germany; Karlsruhe Institute of Technology, Institute for Photon Science and Synchrotron Radiation, Hermann-von-Helmholtz-Platz 1, 76344 Eggenstein-Leopoldshafen, Germany. Electronic address: jubin.kashef@kit.edu.
authors.forename: Jubin
authors.initials: J
authors.lastname: Kashef
mesh_terms: D000818:Animals; D015820:Cadherins / Q000235:genetics / Q000502:physiology*; D002448:Cell Adhesion; D002465:Cell Movement; D003593:Cytoplasm / Q000378:metabolism; D058750:Epithelial-Mesenchymal Transition; D017353:Gene Deletion; D018507:Gene Expression Regulation, Developmental; D049452:Green Fluorescent Proteins / Q000378:metabolism; D007150:Immunohistochemistry; D008856:Microscopy, Fluorescence; D009154:Mutation; D009432:Neural Crest / Q000196:embryology*; D029867:Xenopus Proteins / Q000235:genetics / Q000502:physiology*; D014982:Xenopus laevis / Q000196:embryology* / Q000235:genetics*
chemical_list: D015820:Cadherins; D029867:Xenopus Proteins; D049452:Green Fluorescent Proteins
keywords: Cadherin; Cell migration; Cell–cell adhesion; Neural crest; Xenopus