MATRICES CONTAINING GLYCOSAMINOGLYCANS IN THE DEVELOPING ANTERIOR CHAMBERS OF CHICK AND XENOPUS EMBRYONIC EYES

The fibrous matrix present in the anterior chamber of the chick eye on the 4th day of development has been shown by autoradiography and histochemistry to contain chondroitin sulfate, protein, neutral polysaccharides, and possibly hyaluronic acid (HA). Its synthesis, probably by the mesenchyme of the angle of the eye, is completed by around 10 days of development. In the scanning electron microscope (SEM) it can be seen that, although the matrix thins as the eye grows, it does not disappear until the 15th day. The development of the Xenopus cornea is described; this animal has a matrix in its anterior chamber from soon after the formation of the inner cornea (stage 41) until metamorphosis 7 weeks later. In the SEM, this material appears as a dense, featureless aggregate rather than as a matrix of thick fibres; in the transmission electron microscope, it is seen to be a network of fine filaments containing small dark-staining granules. Histochemistry shows that it contains HA, protein, and neutral polysaccharides. The morphological evidence is compatible with the matrix being made by the inner cornea. The probable major role of the matrix is to separate lens from cornea in establishing the anterior chamber. In the chick embryo, at least, the matrix is also likely to help stabilise the endothelium during its formation. © 1979.