Chondrocyte-specific expression of <i>Dlx5</i> rescued endochondral defects in <i>Dlx5/6</i> null embryos.

<p>(A–D) Lateral views of the heads of P0 neonates with the genotypes shown after staining with alcian blue and alizarin red. Asterisk indicates a missing supraoccipital bone in panel A. Arrows point to supraoccipital bones in panels B–D. (E–G) Dorsal view of the second to fifth lumbar vertebrae from a <i>Dlx5/6^−/−</i> (E), <i>Dlx5/6^−/−</i>; <i>Col2a1-Dlx5^t19/+</i> (F), and <i>Dlx5/6^+/−</i> (G) embryo at E17.5 following alcian blue and alizarin red staining. Since <i>Dlx5/6^−/−</i> embryos are smaller, digital images of L2 to L5 at E17.5 were scaled to the same vertebral size to allow measurements of the relative mineralization of the vertebral bodies. Rostral is at the top. (H) Quantitation of mineralization in the L3 centrum of <i>Dlx5/6^−/−</i> (n = 9), <i>Dlx5/6^−/−; Col2a1-Dlx5^t19/+</i> (n = 3), and <i>Dlx5/6^+/−</i> (n = 9) vertebrae, plotted as average area ± sem. * <i>P</i><0.05; ns, <i>P</i>>0.05. Scale bar = 2 mm in A–D, 0.5 mm in E,F,G.