Histochemical Detection of Arylsulfatase Activity in Sea Urchin Embryos: (arylsulfatase/sea urchin embryo/histochemistry/electron microscopy).

ABSTRACT

Localization of arylsulfatase activity in the sea urchin embryo was determined histochemically by light and electron microscopy. Histochemical observations by light microscopy revealed that the arylsulfatase activity appears after the gastrula stage and that it is restricted to the cells of the aboral ectoderm. The enzyme activity is mainly located in the apical cellular cytoplasm and is associated with lysosome-like structures that are frequently fused with yolk granules. Intense activity is also detected in the region of the endoplasmic reticulum and Golgi apparatus. No enzyme activity is found in the extracellular spaces of embryos.