MONOCLONAL-ANTIBODIES RECOGNIZING STAGE AND REGION-SPECIFIC EPITOPES IN EMBRYONIC MOUSE PALATAL EPITHELIAL-CELLS

Four monoclonal antibodies raised against murine embryonic palatal epi thelium were used to stain frontal cryosections of embryonic mouse hea ds (d 11-15). One antibody (6A11) recognised the nasal epithelium at t he angle of the palate prior to shelf elevation (embryonic d 11-d 13) and the epithelia at the tips of the approximated shelves (embryonic d 14.5). Two further antibodies (2H6 and 3H2) recognised epitopes on th e entire palatal epithelium until shelf elevation (embryonic d 14.5) w hen their expression ceased. The epitope recognised by antibody 6D3 wa s absent from the palatal epithelium until embryonic d 13 when it disp layed region specific expression, being present on the nasal aspect in the midpalate and the tip of the palate posteriorly. On embryonic d 1 4.5 staining of the medial edge epithelia was present in all regions. Whilst the nasal palatal epithelium stained in the anterior and mid re gions, only patchy staining of the oral epithelium was detected. By em bryonic d 15 staining was present throughout the palatal epithelia. Th ese antibodies are directed against intracellular epitopes, possibly k eratins. Indeed, immunoblotting assays revealed that antibody 2H6 reco gnised keratin 18. The developmental regulation of the epitopes recogn ised by the antibodies corresponds with differentiative events occurri ng during murine palatogenesis.