Comparative analysis of glucosephosphate isomerase, lactate dehydrogenase and malate dehydrogenase isozymes in 9 cyprinid species from Italy

The developmental and the tissue-specific expression of glucosephosphate isomerase (GPI), lactate dehydrogenase (LDH) and malate dehydrogenase (MDH) multilocus isozymes were analyzed in samples of Leuciscus cephalus and the adult patterns compared with those of 8 additional Italian cyprinid species: Alburnus alburnus alborella, Chondrostoma genei, L. lucumonis, L. souffia, Rutilus rubilio, R. erythrophthalmus, Scardinius erythrophthalmus and Tinca tinca, the taxonomic status of many of them being uncertain and highly debated. The spatial and temporal patterns of expression obtained generally agree with literature data. Main exceptions are the single expression of GPI-A* and MDH-A* loci of the liver in L. cephalus and the GPI pattern of the eye in all species examined. Since delayed appearence of the subunits coded by the GPI-B* locus and the very early ontogenetic expression of the sMDH-B* locus were found in L. cephalus, the onset of expression of orthologous loci can vary in related species. Genetic structure comparisons support a high genetic divergence of T, tinca from all other species.