Formation of phospholipid nitrogenous bases in euryhaline fish and crustaceans. I. Effects of salinity and temperature on synthesis of phosphatidylserine and its decarboxylation

Abstract

Contribution of base-exchange of serine with other phospholipids for the synthesis of phosphatidylserine (PS), followed by PS decarboxylation to phosphatidylethanolamine (PE) and N-methylation of PE was studied, in vivo and in vitro, in euryhaline fish and crustaceans. Incorporation of [ 3H]serine and [ 3H]ethanolamine into PS, PE and PC was determined to assess metabolic dependence of these three phospholipids in different conditions of salinity and temperature. Salinity has the stronger effect on the PS decarboxylation and later on the methylation of PE species provided by this pathway in tissues of euryhaline fish and crustacea. The specific changes observed in the metabolism of the molecular species synthesized through these pathways might be one mechanism allowing the rapid adaptation of euryhaline fish and crustaceans to different salinity and/or temperature.