Neural crest cell-specific <i>Brca2</i> deletion results in a craniofacial bone phenotype similar to that of the neural crest cell-specific <i>Brca1</i> deletion in mice.

<p>(A) Alcian blue- and alizarin red-stained skulls of control and <i>Brca2</i>:<i>Wnt1-Cre</i> mice at birth. Yellow broken lines indicate osteogenic fronts. Scale bar = 2mm. (B) Quantification of the area ratio of frontal foramen in the frontal bone area. White box represents the mean of each genotype. (C) Quantification of sagittal length. (D) Coronal sections of control and <i>Brca2</i>:<i>Wnt1-Cre</i> frontal bone primordia at E12.5 and E13.5 were double-labeled with RUNX2 (red) and BrdU (green). Broken line describes the osteogenic lineage cell population. Right charts show quantification of the ratio of BrdU-positive cells over RUNX2-positive cells. Scale bar = 50μm. (E) Immunostaining for RUNX2 and TUNEL assay of sections from control and <i>Brca2</i>:<i>Wnt1-Cre</i> embryos at E12.5. Broken line describes the osteogenic lineage cell population. White arrows indicate TUNEL-positive cells. Yellow color represents the non-specific signal from red blood cells. Scale bar = 100μm. as, alisphenoid; bo, basioccipital; bs, basisphenoid; eo, exoccipital; fb, frontal bone; ib, interparietal bone; jb, jugal bone; md, mandible; mx, maxilla; nb, nasal bone; p, palatine; pb, parietal bone; pmx, premaxilla; ppmx, palatal process of maxilla; ppp, palatal process of palatine; ptg, pterygoid; tr, tympanic ring.