Genetic control of phosphoglucose isomerase (PGI) isozymes in Anguilliformes: Differential tissue expression of the duplicate PGI loci

Abstract

The electrophoretic patterns of phosphoglucose isomerase (PGI) in different tissues of 13 species of Anguilliformes, representing 8 families and 2 suborders, have been studied. As in higher teleosts, the overall presence of two PGI loci is confirmed in this order. A substantially uniform tissue pattern of PGI gene expression has been observed among anguilliform species, but differing, to some extent, from that of higher teleosts. These data agree with the generally accepted phylogenesis of Anguilliformes. An exception to this unvaried pattern is observed for Conger conger from the Tyrrhenian Sea: while the PGI-1 expression is always strong in liver, the PGI-1/PGI-2 proportion is quite variable and consistent with a regulatory polymorphism at the PGI-2 locus.