Ontogenetic variations of some enzymes indicentrarchus labrax(Serranidae)

Abstract

The ontogenesis of isozyme patterns of alcohol dehydrogenase (ADH), glycerol-3-phosphate dehydrogenase (α-GPDH), lactate dehydrogenase (LDH), malate dehydrogenase (MDH), glucose-6-phosphate dehydrogenase (G-6-PD) and glucosephosphate isomerase (GPI) in Dicentrarchus labrax was studied.ADH is active only in the liver of the adult; a-GPDH is active in only two tissues in the adult: the A 2 isozyme in white skeletal muscle and the B 2 isozyme in the liver. Differential gene expression was found only for LDH, MDH and GPI, which have polymeric structure. The LDH, MDH and GPI isozymes 30 days after hatching were completely active and showed patterns very similar to those of the adult.Spatial and diachronic variations were related to genetic regulation of expression. Tissue specificity and time of expression during development represent tests of cellular differentiation.