Phylogenetic and taxonomical relationships of the eight species in the melanogaster subgroup of the genus Drosophila (Sophophora) based on the electrophoretic mobility of the major chorion proteins and the eggshell ultrastructure

The eight species of the melanogaster species subgroup of the genus Drosoph ila were compared to each other with respect to: (a) the electrophoretic mo bility of the major chorion proteins under SDS-PAGE; (b) the overall eggshe ll ultrastructure. The phylogenetic tree obtained using the first criterion showed that the eight species are divided into three clusters that contain the species of the melanogaster complex (D. melanogaster, D. sechellia, D. mauritiana and D. simulans), the two species of the yakuba complex (D. yak uba and D. teissieri) and the erecta complex species (D. erecta and D. oren a). This clustering is in agreement to the generally accepted phylogeny of the subgroup based on exclusive criteria. The eggshell ultrastructure of th e species at the main body of the egg revealed that the phylogenetically cl osely related species exhibit similar eggshell structure. We conclude that the criteria applied in this study could be eventually used in groups with unknown phylogeny to trace the phylogenetic relationships of the species.