Figure 4. Qkf^gt/gt mutant mice deficient in Myst4.

Qkf^gt/gt mutant mice deficient in MYST4 exhibit facial and skeletal abnormalities. (A–C) External appearance of Qkf^gt/gt mutant mice versus that of controls at 7 weeks of age. (D and E) Close-up images of the eyes. (F and G) Skeletal preparation of the lower jaw. (H–K) β-Galactosidase reporter activity (blue) representing the high Qkf gene expression domains (H and I) in cartilage primordia of the developing skeletal system at E15.5, (J) primordia of the cerebral cortex and skeletal elements at E12.5, and (K) the adult parietal cortex (Ctx) and hippocampus (Hi). (L) Endogenous Qkf mRNA detected by in situ hybridization in skeletal primordia of the E15.5 hind limb (precipitated silver grains corresponding to Qkf mRNA appear white in dark-field image). Arrows indicate coronoid process in F and G, strongly Qkf–β-galactosidase–positive cells in H and I, telencephalon and mandibular process in J and K, and endogenous Qkf mRNA expressing cells in skeletal primordia in L. (M) In mice, the tibia and the fibula normally fuse in their distal third. (M) The Qkf^gt/gt mutant mice lack the fusion of the tibia and fibula (N) normally observed in wild-type mice. Scale bar: 190 μm (H); 65 μm (I); 160 μm (J); 790 μm (K); 910 μm (L); and 3.6 mm (M and N).