The Rdh10trex/trex mutant hindlimb has a normal complement of skeletal elements at E14.5. Alcian blue staining of cartilage showing all the skeletal elements of the hindlimb. (A) Wild-type; ventral view. (B) Mutant; ventral view (left) and anterior view (right) to more easily observe femur. Ph, phalanges; Mt, metatarsals; Ta, tarsals; Fi, fibula; Ti, tibia; Fe, femur; Pu, pubis; Is, ischium; Il, ilium. Asterisks mark regions of interdigital webbing retained by mutant autopod.