Tooth germ epithelial-mesenchymal interactions in tissue culture

The usefulness of the tooth germ in culture arises from the fact that it exemplifies those fundamental attributes of development, cell proliferation, cytodifferentiation, and morphogenesis, which we expect to find in the development of any metazoan organism. In culture, as in the organism, such development takes place in 3 dimensions. This study was undertaken to determine if it is possible to uncouple, by using 2 dimensions, cytodifferentiation from morphogenesis. Under the conditions used, cytodifferentiation in culture was not apparent (at the light microscope level). However, the following interesting observations were made: Cell populations arising from the same types of explants (enamel organ/enamel organ or dental papilla/dental papilla) readily flow together. Cell populations arising from dissimilar types of explants (enamel organ/dental papilla) form sharp boundaries at their interfaces. Additionally, cell populations arising from intact tooth germs differ from those arising from either enamel organs or dental papillae.