Nucleotide polymorphism at the alcohol dehydrogenase locus of Drosophila melanogaster.

The sequencing of eleven cloned Drosophila melanogaster alcohol dehydrogenase (Adh) genes from five natural populations has revealed a large number of previously hidden polymorphisms. Only one of the 43 polymorphisms results in an amino acid change, the one responsible for the two electrophoretic variants (fast, Adh-f, and slow, Adh-s) found in nearly all natural populations. The implication is that most amino acid changes in Adh would be selectively deleterious.