Duplicate loci for supernatant and mitochondrial malic enzymes in vendace, Coregonus albula (L.).

There is electrophoretic variation in the vendace (Coregonus albula L.) supernatant malic enzyme (MEs). This is the first observed case of variation of this enzyme in salmonids. The phenotypic distribution among 33 populations studied indicates, that both supernatant and mitochondrial (MEm) malic enzymes are encoded by a duplicate pair of loci, Me-(1,2) then represent the mitochondrial and Me-(3,4) the supernatant form of the enzyme. Both pairs seem to contain one fixed and one variable locus. At both variable loci, Me-2 and Me-4, four alleles were found segregating and their products combine as tetramers within, but not between pairs. At Me-4 extensive between population heterogeneity was observed.