[PDF][PDF] A conserved Pbx-Wnt-p63-Irf6 regulatory module controls face morphogenesis by promoting epithelial apoptosis

E Ferretti, B Li, R Zewdu, V Wells, JM Hebert… - Developmental cell, 2011 - cell.com
E Ferretti, B Li, R Zewdu, V Wells, JM Hebert, C Karner, MJ Anderson, T Williams, J Dixon…
Developmental cell, 2011cell.com
Morphogenesis of mammalian facial processes requires coordination of cellular
proliferation, migration, and apoptosis to develop intricate features. Cleft lip and/or palate
(CL/P), the most frequent human craniofacial birth defect, can be caused by perturbation of
any of these programs. Mutations of WNT, P63, and IRF6 yield CL/P in humans and mice;
however, how these genes are regulated remains elusive. We generated mouse lines
lacking Pbx genes in cephalic ectoderm and demonstrated that they exhibit fully penetrant …
Summary
Morphogenesis of mammalian facial processes requires coordination of cellular proliferation, migration, and apoptosis to develop intricate features. Cleft lip and/or palate (CL/P), the most frequent human craniofacial birth defect, can be caused by perturbation of any of these programs. Mutations of WNT, P63, and IRF6 yield CL/P in humans and mice; however, how these genes are regulated remains elusive. We generated mouse lines lacking Pbx genes in cephalic ectoderm and demonstrated that they exhibit fully penetrant CL/P and perturbed Wnt signaling. We also characterized a midfacial regulatory element that Pbx proteins bind to control the expression of Wnt9b-Wnt3, which in turn regulates p63. Altogether, we establish a Pbx-dependent Wnt-p63-Irf6 regulatory module in midfacial ectoderm that is conserved within mammals. Dysregulation of this network leads to localized suppression of midfacial apoptosis and CL/P. Ectopic Wnt ectodermal expression in Pbx mutants rescues the clefting, opening avenues for tissue repair.
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