Genetic variation and immunochemical properties of L-malate: NAD⁺ oxidoreductase isozymes in the bandicoot, isoodon macrourus

A genetic polymorphism for the soluble isozyme (MDH-A₂) of malate dehydrogenase (L-malate: NAD⁺ oxidoreductase; EC 1.1.1.37) was found in a Townsville-Inkerman population of short-nosed bandicoots, 1. macrourus. The enzyme seems to be inherited in a normal autosomal codominant manner. The gene frequencies for the MDH-A and MDH-A′ alleles were 0·82 and 0·18 respectively. The genotypic frequencies indicated that the population was in Hardy-Weinberg equilibrium. None of 22 pouch young from seven litters expressed a phenotype inconsistent with its mother’s genotype, assuming autosomal co dominance. Other populations of I. macrourus and of the long-nosed bandicoot (Perameles nasuta) exhibited only the MDH-A allele. Homologous relationships of bandicoot MDH-A₂ and MDH-B₂ isozymes to those of other vertebrates were established by immunochemical studies.