title: Positional signalling and specification of digits in chick limb morphogenesis.
abstract: The interpretation of positional information can provide the basis for pattern formation in limb morphogenesis. The gradient in positional information along the antero-posterior axis, which is specified with respect to a localised boundary region, can be modified by grafting this region to successive positions along the axis. The pattern of digits obtained is consistent with a model based on diffusion of a labile morphogen and is thus similar to models proposed for the development of pattern in invertebrates.
mesh_terms: D000818:Animals; D002642:Chick Embryo; D004475:Ectoderm; D009024:Morphogenesis; D014921:Wings, Animal / Q000196:embryology*