Cadherin interplay during neural crest segregation from the non‐neural ectoderm and neural tube in the early chick embryo. Issue 7 (22nd May 2017)

• Record Type: Journal Article
• Authors: Dady, Alwyn; Duband, Jean‐Loup
• Is Part Of: Developmental dynamics. Volume 246:Issue 7(2017)
• Page Start: 550
• Page End: 565
• Publication Date: 2017-05-22
• Subjects: Chick embryo -- neural crest -- cell sorting -- EMT -- E‐cadherin -- N‐cadherin -- Cadherin‐6B; Morphogenesis -- Periodicals; Anatomy -- Periodicals; Anatomie -- Périodiques; Biologie du développement -- Périodiques; 571.833
• DOI: 10.1002/dvdy.24517
• Languages: English
• ISSNs: 1058-8388

Abstract

Abstract : Background : In the avian embryo, neural crest (NC) progenitors arise in the neuroectoderm during gastrulation, long before their dissemination. Although the gene regulatory network involved in NC specification has been deciphered, the mechanisms involved in their segregation from the other neuroectoderm‐derived progenitors, notably the epidermis and neural tube, are unknown. Because cadherins mediate cell recognition and sorting, we scrutinized their expression profiles during NC specification and delamination.Results : We found that the NC territory is defined precociously by the robust expression of Cadherin‐6B in cells initially scattered among other cells uniformly expressing E‐cadherin, and that NC progenitors are progressively sorted and regrouped into a discrete domain between the prospective epidermis and neural tube. At completion of NC specification, the epidermis, NC, and neural tube are fully segregated in contiguous compartments characterized by distinct cadherin repertoires. We also found that Cadherin‐6B down‐regulation constitutes a major event during NC delamination and that, with the exception of the caudal part of the embryo, N‐cadherin is unlikely to control NC emigration.Conclusions : Our results indicate that partition of the neuroectoderm is mediated by cadherin interplays and ascribes a key role to Cadherin‐6B in the specification and delamination of the NC population. Developmental Dynamics 246:550–565, 2017 . © 2017 Wiley Periodicals, Inc. Key Findings: Cadherin‐6B marks very precociously the neural crest territory during the initial steps of their specification. Cadherin‐6B may be implicated in the sorting of the neural crest progenitors from the other neuroectodermal progenitors. Downregulation of Cadherin‐6B and not of N‐cadherin constitutes the triggering event of neural crest cell delamination. E‐cadherin and N‐cadherin define the epidermal and neural compartments derived from the neurectoderm only secondarily after neural crest specification.