Figure 6.

Skeletal staining illustrating non-complementation between Ptch1^DL and Ptch1-LacZ mutant alleles.

E18.5 Ptch1^DL heterozygotes (a, c, e, g, i, k) and Ptch1^DL/Ptch1-LacZ mutants (b, d, f, h, j, l). Lateral views of skulls (a, b) with red arrow showing abnormal flexure at skull and nasal juncture. Dorsal view of skulls (c, d). Black arrow in (d) illustrates lack of lambdoid suture. Ventral view of skull with mandibles removed (e, f) with the absence of the presphenoid bone and the underdevelopment of the palatal shelves (red asterisk), and the aberrant morphology of the alisphenoid bone (white arrow) marked in the Ptch1^DL/Ptch1-LacZ mutants. (g, h) Lateral view of dentary bones. (i, j) Ribcage in ventral view. (k, l) forelimbs.

Key: A, anterior; ap, angular process; Bo, basioccipital; Bs, basisphenoid; cdp, condylar process; crp, coronoid process; Fr, frontal bone; Hy, hyoid; Ip, interparietal bone; M, manubrium; Mx, palatine process of the maxilla; N, nasal bone; P, posterior; Pl, palatine; Pr, parietal bone; Ps, presphenoid; Px, premaxilla; X, xiphoid process.