Polymorphism of Blood Plasma Esterases in Natural Population of Giant Toad, Bufo marinus Linn. (Amphibia: Bufonidae)

Abstract

Starch gel electrophoretic analysis of esterases in the plasma of the giant toad, Bufo marinus Linn., resolved three sets of electromorphs presumably products of three independently-segregating loci, migrating to the anodal region. These esterases were identified to be of carboxyesterase type based on the affinity to a-and B-naphthol acetates as substrates. 

Estimation of the allelic frequency revealed that all three loci showed polymorphism based on 5% criterion of polymorphism. Goodness-of-fit test between the observed genotypic frequencies with the expected frequencies in each of the EST locus showed the toad population was not at Hardy-Weinberg equilibrium. This could be attributed to heterozygote deficiency in each of the locus.