Studies on the closure of the secondary palate: I. Autoradiographic study in the normal mouse embryo

The incorporation of radioactive sulphate in 11 to 17-day-old mouse embryos, with special reference to closure of the secondary palate, has been studied by autoradiography after injection of 35S-labelled sulphate. A well marked 35S incorporation could be demonstrated in the connective tissue of the palatine shelves, and is assumed to be representative of the synthesis of acid mucopolysaccharides. It is suggested that the method can also be applied in teratogenic experiments.