Analysis of isozyme loci in the face fly,Musca autumnalis DeGeer

Vertical polyacrylamide gel electrophoresis was used to resolve enzymes at 50 putative loci in Iowa face flies, a recently arrived, colonizing, Palearctic species. Sixty-two percent of the 50 loci were polymorphic. The mean number of alleles per polymorphic locus was 3.2 +/- 1.38; the mean among all loci was 2.38 +/- 1.62 alleles. The effective number of alleles among 50 loci was 1.4 +/- 0.62. Mean observed and expected heterozygosities for the 50 face fly loci were 0.167 +/- 0.037 and 0.186 +/- 0.031, respectively. Comparison of the electrophoretic data for Musca autumnalis and for M. domestica L. showed similar high levels of gene diversity. A survey of gene diversity at 12 loci among six geographically independent laboratory colonies demonstrated statistically significant genetic differentiation that was probably due to drift after colonization.