Fig. 4. Craniofacial analysis of wild-type and BAenh^–/– mice at P1. (A,C,E,G,I,K,M,O) wild-type; (B,D,F,H,J,L,N,P) BAenh^–/– mutant mice. (A,B) Lateral view, (C-F) ventral view, (G-P) isolated bones and cartilages. (A-D) The mandible (ma) is hypoplastic and deformed, and Meckel's cartilage (arrows in C and D) is truncated in the mutant mouse (B,D). (E,F) Tympanic rings (ty) are thickened and deformed in the mutant mouse (F, compare arrows in E and F). Fusion of the bilateral palatine processes observed in the wild type mouse (E, dashed line) is absent in the mutant mouse (F, dashed lines). Asterisk in F indicates the presphenoid bone. (G,H) In the wild-type mouse, the secondary palate is formed by the fusion of bilateral palatine processes (arrows). In the BAenh^–/– mouse, the palatine processes are not formed so that the presphenoid (ps) becomes visible. (I,J) Palatine bones viewed end on. Compare black arrows in I and J, which indicate fused palatine processes and absence of palatine processes, respectively. An asterisk indicates the presphenoid bone. (K,L) Ventral views of the mandibles. Note that the mandible in the BAenh^–/– mouse is shorter and deformed. The angle between the left and right mandible is wider than that in the wild-type mouse. (M,N) Lateral views of the mandibles. Note that the articular process (ap) in the BAenh^–/– mouse is severely hypoplastic and an ectopic process (black arrow) is formed. (O,P) Lateral views of middle ear cartilages and tympanic ring. In the mutant mouse, Meckel's cartilage (mc) is truncated, and the tympanic ring (ty) is shortened and thickened. Black and red arrows indicate the gonial bone and manubrium of the malleus, respectively. Note that the gonial bone is hypoplastic and the projection of the manubrium is abnormal in the BAenh^–/– mutant. bs, basisphenoid; crp, coronoid process; h, hyoid; I, incus; lo, lamina obturans; m, malleus; mc, Meckel's cartilage; oc, otic capsule; pa, palatine; pt, pterygoid; tc, thyroid cartilage.

Return to article