... is largely unknown. Here, we report that Hand2 negatively regulates intramembranous ossification of the mandible by directly inhibiting the transcription factor Runx2, a master regulator of osteoblast differentiation. Hand proteins physically interact with Runx2, suppressing its DNA binding...

... morphology. * Author for correspondence (e-mail: rich.schneider@ucsf.edu ) 16 1 2008 © 2008. 2008 Epithelial-mesenchymal interactions BMP signaling Mandibular primordia Neural crest Intramembranous ossification Quail-duck chimeras Evolutionary developmental biology...

... clearly present, albeit also proportionally smaller, in the mutant embryos( Fig. 7A-F )( Hanken and Hall, 1993 ). This could suggest either that there is a significant unrecognized dermal bone contribution to these structures or that intramembranous ossification can compensate for the reduction...

..., including excessive intramembranous ossification all along the perichondrial border and the formation of ectopic cartilage masses. Looking for possible culprits for these latter processes, we analyzed hedgehog signalling topography and intensity by monitoring the expression of the hedgehog effectors Patched...