Dr. Robert E Maxson
The overall interest of the Maxson laboratory is the molecular genetic basis of embryonic pattern formation. We focus on processes that regulate the development of the calvaria, the flat bones that compose the top of the skull. These bones are derived from populations of neural crest and mesoderm that undergo extensive migration and proliferation as they develop into the exquisitely patterned calvarial bones. Between the bones are sutures, fibrous structures that form flexible joints uniting the bones, and that also serve as sources of stem cells that enable the bones to grow in coordination with the brain. Using genetic approaches in humans and mice, we have identified several genes that participate in the development of the calvarial bones and sutures. These include MSX2, which when mutated causes craniosynostosis, the fusion of the calvarial bones at the sutures, and Twist1, also required for suture development. Our most recent work involves an interaction between Twist1 and a related transcription factor, Tcf12. This interaction has a central role in the development of the coronal suture as well as in the pathophysiology of Saethre-Chotzen syndrome, a human disorder that results in craniosynostosis. We have investigated this interaction in mice, and in a collaboration with Gage Crump, in zebrafish. Current work focuses on how Twist1 and Tcf12 influence osteogenic precursor proliferation and differentiation, and how deficiencies in these processes lead to craniosynostosis.