BCL11B regulates sutural patency in the mouse craniofacial skeleton

The transcription factor BCL11B plays essential roles during development of the immune, nervous, and cutaneous systems. Here we show that BCL11B is expressed in both osteogenic and sutural mesenchyme of the developing craniofacial complex. Bcl 11 b −/− mice exhibit increased proliferation of osteoprogenitors, premature osteoblast differentiation, and enhanced skull mineralization leading to synostoses of facial and calvarial sutures. Ectopic expression of Fgfr 2 c, a gene implicated in craniosynostosis in mice and humans, and that of Runx 2 was detected within the affected sutures of Bcl 11 b −/− mice. These data suggest that ectopic expression of Fgfr 2 c in the sutural mesenchyme, without concomitant changes in the expression of FGF ligands, appears to induce the RUNX2-dependent osteogenic program and craniosynostosis in Bcl 11 b −/− mice.