The molecular evolution of the alcohol dehydrogenase and alcohol dehydrogenase-related genes in the Drosophila melanogaster species subgroup

The DNA sequences of the Adh genes of three members of the Drosophilamelanogaster species subgroup have been determined. This completes the Adhsequences of the eight species of this subgroup. Two species, D. yakuba andD. teissieri, possess processed Adh pseudogenes. In all of the species ofthe subgroup, a gene of unknown function, Adhr, is located about 300 bp 3'to Adh. Although this gene is experiencing a higher rate of synonymoussubstitution than Adh, it is more constrained at the amino acid level.Phylogenetic relationships between all eight members of the melanogastersubgroup have been analyzed using a variety of methods. All analysessuggested that the D. yakuba and D. teissieri pseudogenes have a singlecommon ancestor, rather than evolving independently in each species, andthat D. melanogaster is the sister species to D. simulans, D. sechellia,and D. mauritiana. The evolutionary relationships of the latter threespecies remain equivocal.