Discrimination of walleye, Stizostedion vitreum vitreum (Mitchill), stocks by isozyme analysis with cellulose acetate

Summary. Five walleye, Stizosfedion vitreum vitreum (Mitchill), populations from within the state of Minnesota were examined for isozyme gene frequencies. Of 26 loci identified and scored, nine polymorphic loci were found. The ADH*, MDH-3* and PROT-4* loci were found to be the most informative for distinguishing the populations. A north-south cline in the frequency of PROT-4* alleles was found, with a higher frequency of the fast allele being found in the southern population. This is probably a reflection of genetic isolation caused by glaciation. Cellulose acetate was used to resolve the isozymes. The advantages of cellulose acetate over starch in terms of decreased run time, smaller sample and stain volumes and superior resolution advocate the use of cellulose acetate for fish isozyme analyses. Comparisons between starch and cellulose acetate separations showed similar results with some exceptions. Cellulose acetate resolved FH* and PROT-2* polymorphisms that were not resolved on starch, but failed to resolve the MDH-1 locus. These differences did not affect the results.