title: Ultrastruct analysis of the apical ectodermal ridge duri;g vertebrate limb morphogenesis. II. Gap junctions as distinctive ridge structures common to birds and mammals.
mesh_terms: D000818:Animals; D001717:Birds / Q000196:embryology; D004475:Ectoderm / Q000648:ultrastructure*; D005121:Extremities / Q000196:embryology* / Q000648:ultrastructure; D005614:Freeze Fracturing; D007365:Intercellular Junctions / Q000648:ultrastructure; D008322:Mammals / Q000196:embryology; D008854:Microscopy, Electron; D009024:Morphogenesis