Sun, YeTeng, IanHuo, RandiRosenfeld, Michael GOlson, Lorin ELi, XiaokunLi, Xue2013-05-142012Sun, Ye, Ian Teng, Randi Huo, Michael G. Rosenfeld, Lorin E. Olson, Xiaokun Li, and Xue Li. 2012. Asymmetric requirement of surface epithelial β-catenin during the upper and lower jaw development. Developmental Dynamics 241(4): 663-674.1058-8388http://nrs.harvard.edu/urn-3:HUL.InstRepos:10628434Background: Intercellular communication between epithelial and mesenchymal cells is central to mammalian craniofacial development. β-catenin is the gateway of canonical Wnt signaling, one of the major evolutionarily conserved cell–cell communication pathways in metazoa. In this study, we report an unexpected stage- and tissue-specific function of β-catenin during mammalian jaw development. Results: Using a unique mouse genetic tool, we have discovered that epithelial β-catenin is essential for lower jaw formation, while attenuation of β-catenin is required for proper upper jaw development. Changes in β-catenin in vivo alter major epithelial Fgf8, Bmp4, Shh, and Edn1 signals, resulting in partial transcriptional reprogramming of the neural crest-derived mesenchyme, the primary source of jawbones. Conclusions: The Wnt/β-catenin signal coordinates expression of multiple epithelial signals and has stage-specific asymmetric functions during mammalian upper and lower jaw development. In addition, these findings suggest that evolutionary changes of the canonical Wnt/β-catenin signaling pathway may lead to innovation of jaws.en-UScraniofacialpharyngeal archß-cateninFgf8Bmp4ShhendothelinDlx5Hand2CrejawWntJournal Article2013-05-1410.1002/dvdy.23755