HYALINE LAYER IS A COLLAGEN-CONTAINING EXTRACELLULAR MATRIX IN SEA-URCHIN EMBRYOS AND REAGGREGATING CELLS

Evidence is given to support the classification of the hyaline layer of sea urchin embryos and reaggregating cells as a collagen-containing extracellular matrix. Ruthenium red staining shows the presence of striated fibril-like structures, dense spheroids, crystalline lattice structures and filamentous material. Collagenase digestion causes disappearance of the fibril-like structures; hyaluronidase treatment causes a diminution of other matrix components, but does not affect the fibrillar structures. The hyaline layer maintains the integrity of the embryo and is also involved in morphogenesis, which are among the functions of extracellular matrices. © 1979.