Fig. 5. A11^13hd hindlimb phenotype. (A) The arrowhead points to the normal tibia and fibula fusion point and broad arrow points to the calcaneus bone in wild-type hindlimb. Mice of A11^13hd/+ D11^+/+ or A11^-/- D11^+/+ genotypes showed similar more distal separation of tibia and fibula, while A11^13hd/13hd D11^+/+ mice showed more extreme tibia, fibula separation (thin arrows) when compared with wild type. (B) Substitution of the A11^- allele by an A11^13hd allele in either A11^+/- D11^-/- or A11^+/- D11^+/- mutants resulted in greater separation of tibia and fibula (arrows). (C) Ventral views of isolated autopods of hindlimbs. A11^13hd/13hd D11^+/+ mutants had a severely truncated calcaneus compared with wild type (arrows). A11^-/- D11^+/+ mutants were normal. c, calcaneus; F, fibula; T, tibia.