title: Ultrastructural analysis of the apical ectodermal ridge during vertebrate limb morphogenesis. 1. the human forelimb with special reference to gap junctions.
mesh_terms: D001132:Arm / Q000196:embryology*; D004475:Ectoderm / Q000648:ultrastructure*; D005614:Freeze Fracturing; D006801:Humans; D007365:Intercellular Junctions / Q000648:ultrastructure; D008854:Microscopy, Electron; D008855:Microscopy, Electron, Scanning