Transforming growth factor–β3 is required for secondary palate fusion

Mice lacking TGF–β3 exhibit an incompletely penetrant failure of the palatal shelves to fuse leading to cleft palate. The defect appears to result from impaired adhesion of the apposing medial edge epithelia of the palatal shelves and subsequent elimination of the mid–line epithelial seam. No craniofacial abnormalities were observed. This result demonstrates that TGF–β3 affects palatal shelf fusion Dy an intrinsic, primary mechanism rather than by effects secondary to craniofacial defects.