Acid mucopolysaccharides in the development of the Pacific great skate, Raja binoculata

Abstract

Histochemical treatments specific for hyaluronic acid, C-S-A/C, C-S-B and heparin were applied to a series of Pacific great skate (Raja binoculata) embryos from cleavage to immediate prehatching stages, in order to characterize histochemically the AMPS present in the embryos and to study the events leading to AMPS localization in the adult. A progression was observed: (a) intracellular neutral polysaccharides in cleavage stages, (b) a combination of extracellular polysaccharides and weakly acidic AMPS (hyaluronic acid) associated with cell processes in neurulating stages, (c) extracellular strongly acidic AMPS (chondroitin sulphates) in later stages, particularly in areas of cartilage development. In neurulating embryos hyaluronic acid appeared in quantity between adjacent tissues, suggestive of some developmental significance for this compound. Hyaluronic acid also appeared after neurulation in close association with developing gut and mesonephros. Histochemical localization of these compounds in immediate prehatching stages agreed with previously reported biochemical analyses of shark skin and cartilage, i.e. C-S-B occurred in skin and C-S-A/C was a major component of cartilage matrix.