title: Structural analysis of extracellular matrix prior to the migration of cephalic neural crest cells.
abstract: Cephalic neural crest cells enter cell free areas containing abundant extracellular matrix (ECM). Previous histochemical studies have identified both sulfated and non-sulfated glycosaminoglycans within this matrix. In the present study, ultrastructural examination of the ECM demonstrated an anastomosing network of pleomorphic, cetyl pyridinium chloride-dependent strands within cell free spaces and in association with the basement membrane of the surface ectoderm. Thin section analysis revealed that the strands consisted of three components: (1) 3-5 nm filament meshwork; (2) electron dense amorphous material and (3) 30 nm granules. In contrast, the ECM associated with the basement membrane consisted principally of a continuum of electron dense, amorphous material. The molecular ordering of ECM within crest cell pathways was compared to the well-characterized, hyaluronate-rich, premigratory matrix of cardiac jelly.
mesh_terms: D000818:Animals; D001485:Basement Membrane / Q000032:analysis; D002465:Cell Movement; D002642:Chick Embryo; D004699:Endocardium / Q000032:analysis; D005110:Extracellular Space / Q000032:analysis*; D006025:Glycosaminoglycans / Q000032:analysis*; D006820:Hyaluronic Acid / Q000032:analysis*; D046911:Macromolecular Substances; D008855:Microscopy, Electron, Scanning; D009432:Neural Crest / Q000166:cytology*
chemical_list: D006025:Glycosaminoglycans; D046911:Macromolecular Substances; D006820:Hyaluronic Acid