TRANSFORMING GROWTH FACTOR-BETA-3 IS REQUIRED FOR SECONDARY PALATE FUSION

Mice lacking IGF-beta 3 exhibit an incompletely penetrant failure of t he palatal shelves to fuse leading to cleft palate. The defect appears to result from impaired adhesion of the apposing medial edge epitheli a of the palatal shelves and subsequent elimination of the mid-line ep ithelial seam. No craniofacial abnormalities were observed. This resul t demonstrates that TGF-beta 3 affects palatal shelf fusion by an intr insic, primary mechanism rather than by effects secondary to craniofac ial defects.