Sox2 is required for palate formation

Objectives: During organogenesis, the transcription factor Sox2 is critical for maintaining the pluripotency of early embryonic cells and regulating the formation of several epithelial tissues. Sox2 is widely expressed in the ectoderm-derived epithelial tissues of craniofacial organs, such as the palate, tooth and tongue. Classical research has suggested that early palate formation develops via epithelial-mesenchymal interactions. However, the function of Sox2 in the palatal epithelium during palate formation remains largely unknown.
Methods: To determine the role of Sox2 in the palatal epithelium during palatogenesis, we generated K14-Cre; Sox2^fl/fl mice to ablate Sox2 in the palatal epithelium.
Results: In this study, we found that Sox2 expression shows a specific pattern in the palatal epithelium during palatogenesis. In the oral-nasal view, Sox2 exhibits higher expression in the oral side and lower expression in the tip region and nasal side. In the anterior-posterior view, there are more Sox2+ cells in the palatal rugae and fewer Sox2+ cells in the regions between the palatal rugae. Specific deletion of Sox2 in the palatal epithelium results in a cleft between the primary and secondary palate, whereas palatal shelves of the secondary palate are completely fused. In addition, palatal rugae fail to form in K14-Cre; Sox2^fl/fl mice.
Conclusions: Sox2 plays a critical role in the fusion of the primary and secondary palate and in the formation of palatal rugae.