DISTRIBUTION OF C-CAM IN DEVELOPING ORAL-TISSUES

C-CAM is a cell surface glycoprotein that is involved in cell adhesion and may play a role in histogenesis and organogenesis. It is a member of the carcinoembryonic antigen (CEA) gene family, which is a subfami ly of the immunoglobulin gene superfamily. We have analyzed the expres sion of C-CAM during normal and disturbed craniofacial development in the mouse by immunohistochemistry and in situ hybridization. Developme ntal disturbances were induced by retinoic acid (RA) treatment of preg nant mice. Normal and malformed fetuses were examined on days 14, 15, 16, 17 and 18 of gestation. The expression of C-CAM was detected first at day 16. With age, the signal became gradually stronger. C-CAM was detected in the epithelia of both ectodermal and mesodermal origin, in cluding oral and respiratory epithelia, epithelia of the developing ve ssels, glands and their ducts. In the RA-treated fetuses, the expressi on of C-CAM was higher in the epithelium of the oral cavity than in th at of the nasal cavity, with a distinct borderline between differentia ting nasal and oral epithelium of the palatal shelves. However, the su bmucosal nasal glands and ducts showed higher expression than oral gla nds in both normal and RA-treated mice. The expression of C-CAM did no t differ significantly between control and RA-treated animals. The pre sence of C-CAM in all proliferating craniofacial epithelia indicates t hat this molecule may play an important role in development.