Fig. 2.

Nell-1 inactivation in CNCCs results in frontonasal bone hypoplasia and micrognathia in Nell-1^Wnt1KO newborn mice. a As a result of Nell-1 inactivation in CNCCs, Nell-1 mRNA, and protein expression decreased only in the frontonasal bones (Nell-1^Wnt1KO (f) and not in the parietal bones (Nell-1^Wnt1KO P); b The craniofacial tissues stained positive for X-gal, with the frontonasal and mandibular bones being particularly targeted in Nell-1^Wnt1-R26RKO mice; c gross appearance and skeletal staining showed no visible defects of the appendicular and axial bones in neonatal Nell-1^Wnt1KO mice; d detailed analyses of the cranial vault of newborn mice exhibited significant hypoplasia of the frontonasal bones, while the synchondroses of the cranial base were unaffected as demonstrated by skeletal staining, high resolution micro-CT imaging, and quantification as measured by bone volume (BV/TV), bone mineral density (BMD), frontal bone thickness and defect area, the suture width as well as the anteroposterior length of calvarial vault; e Nell-1^Wnt1KO mice exhibited significantly smaller and shorter mandibles (micrognathia) with decreased BV/TV and BMD. NS no significance; *P < 0.05; **P < 0.01; ***P < 0.005; ****P < 0.001; n = 3 for a; n = 6 for d and (e)