AMYLASE POLYMORPHISM IN CRUSTACEA DECAPODA - ELECTROPHORETIC AND IMMUNOLOGICAL STUDIES

Alpha-amylase polymorphism was studied in 40 species of crustaceans be longing to four infraorders of Decapoda. Specific activities of alpha- amylases from hepatopancreas extracts of the same species were also me asured. Very low specific activities were measured for Carcinus, Munid a, Nephrops and Palinurus, whilst high activities were measured for sh rimps and crabs. Amylases from one species of each of the four infraor ders of Decapoda were purified by affinity chromatography. Very few di fferences in the specific activities of the pure enzymes were detected . The amylase content of crude extracts ranges between 0.1% of total p rotein, from the hepatopancreas in Carcinus maenas and Eupagurus bernh ardus, to 1% in Penaeus vannamei and Procambarus clarkii.The apparent molecular weight, determined by denaturating electrophoresis, was 55 k Da for Eupagurus and Procambarus amylases but only about 30 kDa for Ca rcinus and Penaeus amylases. Using immunodiffusion, rocket immunoelect rophoresis and enzyme inhibition with antibodies against Palaemon serr atus alpha-amylase, we have shown that all the Decapod alpha-amylases are immunologically related but that they are different from those of Copepods, Bacillus or pig pancreatic amylases. The use of these data f or phylogenetic analysis is discussed.