The Association of Mucopolysaccharides with Morphogenesis of the Palate and Other Structures in Mouse Embryos

Acid mucopolysaccharides have been postulated to occur in the palatine shelves of mouse embryos on the basis of metachromatic staining with toluidine blue (Walker & Fraser, 1956), and this idea has since been supported by results from radioautography with S35 (Larsson, Bostrom, & Carlsoo, 1958). It was not known which structural component of the tissue contained this substance, but, since aldehyde fuchsin-positive material existed in the same area, the possibility was raised that the component was a network of elastic fibres (Walker & Fraser, 1956). The first purpose of the present paper is to describe further histochemical and radioautographic investigations of this problem, supplemented by electron microscopic observations of palatine shelf tissue.