Genetic differentiation of Drosophila melanogaster populations as assessed by two-dimensional electrophoresis

Seven populations of Drosophila melanogaster, representing a worldwide distribution, were compared using two-dimensional protein gel electrophoresis. A total of 611 protein spots was scored, which probably represent a sample of over 500 loci that were surveyed. Of the protein spots scored, 521 spots were found to be invariant, but another 90 spots were found to be variable among the populations. Of these variable protein spots, 12 were found to be present in only one population. All the populations, except one, had at least one protein spot restricted to itself. However, the Japanese population had by far the most, with five protein spots restricted to this one population, which has been observed in previous studies of private alleles in oriental populations. The mean genetic similarity (F) found among the seven populations was 0.965, with a range of between 0.956 and 0.977. This is similar to previous reports of lower variation found in population genetic surveys using two-dimensional electrophoresis. It was found that the historical relationships among these populations was somewhat congruent with the geographic distribution of the populations, but as in previous studies, it was not exactly coincident.