PROLINE BETAINE: A UNIQUE OSMOLYTE IN AN EXTREMELY EURYHALINE OSMOCONFORMER

Abstract

The extremely euryhaline mollusc, Elysia chiorotica, does not utilize intracellular free amino acids for cell volume regulation during osmotic stress. Instead, Elysia utilizes an osmolyte previously unknown from animals, proline betaine. Although proline betaine occurs in some plants and Elysia forms a symbiosis with an algae, the proline betaine in Elysia seems to be a product of the animal.