Genetic and in vitro molecular hybridization of malate dehydrogenase isozymes in interspecific bass (Micropterus) hybrids

Summary Supernatant malate dehydrogenase (MDH) isozymes (as visualized by starch gel electrophoresis) are encoded by two distinct gene loci in both the largemouth and smallmouth bass. When an interspecific F1 hybrid is formed between these two fish, a unique MDH isozyme is generated. The results of freeze‐thaw molecular hybridization (which is the first application of this technique to MDH) indicate that this unique isozyme in the F1 hybrid is a heterodimer composed of one subunit of each parental type. The F1 hybrids produced F2 hybrids which in turn formed the F3 hybrid population. The inheritance of alleles at the MDH‐B locus is consistent with a single Mendelian autosomal locus. Furthermore, there is no evidence of linkage between the lactate dehydrogenase‐E locus and the MDH‐B locus.