Esterase polymorphisms in the skipjack tuna, Katsuwonus pelamis

Esterase polymorphism in the Adriatic sardine (Sardina pilchardus Walb.). 1. Electrophoretic and biochemical properties of the serum and tissue esterases

At least four zones of esterase activity designated I, II, III and IV were found after electrophoretic separation of sera and soluble extracts of sardine tissues on starch gel. Each zone consisted of one or more bands that were distinguishable from other zones by electrophoretic mobility, substrate specificity and sensitivity to various inhibitors. Polymorphism was noted in zones I, II and III, while zone IV consisted of a single band. A genetic interpretation of the polymorphism was given for zone I esterases in the tissue, which appears to be controlled by four codominant alleles. The zones designated I, II and IV in the sera and II, III and IV in the liver were characterized as carboxylesterases, zone II in the sera was the only one with cholinesterase activity, while zone I in the liver tissue was unclassifiable.

Comparative study of esterases in brains of the vertebrates

Disc gel electrophoretic patterns of esterases obtained in the buffer (0.1 M Tris-HCl buffer pH 7.4) extracts of the brains of twelve species belonging to various classes of vertebrates ranging from fishes to mammals are compared. Substrate specificity and inhibitor sensitivity is used to classify the enzymes into different classes of esterases. The pattern obtained does not suggest distribution of any specific enzymes to a particular class of vertebrates nor does it suggest any evolutionary change from fish to mammals. Some fast moving bands are observed in fishes and amphibians. Esterases with active thiol groups (Aryl and Esdp esterases) exhibit wide distribution among the species studied. The enzymes which are resistant to inhibition by eserine, pCMB and DFP (Acetyl and ER esterases) are present in the tetrapods studied.

Biochemical genetics of Fundulus heteroclitus (L.). III. Inheritance of isocitrate dehydrogenase (Idh-A and Idh-B), 6-phosphogluconate dehydrogenase (6-Pgdh-A), and serum esterase (Est-S) polymorphisms

Starch gel electrophoresis has shown that natural populations of Fundulus heteroclitus have variants at four enzyme-coding loci: Idh-A, Idh-B, 6-Pgdh-A, and Est-S. Analysis of the phenotypic distribution of the F1 generation suggests that each of the variants segregates as autosomally inherited codominant alleles. Tissue specificity and intracellular localization were also determined for the IDH and 6PGDH isozymes.