Regulation of the tissue specificity of an enzyme by a cis-acting genetic element: evidence from interspecific Drosophila hybrids.

Homologous genes for alcohol dehydrogenase (alcohol:NAD+ oxidoreductase, EC 1.1.1.1) are expressed in qualitatively different patterns during the development of two closely related species of Hawaiian Drosophila. In interspecific hybrids, each parental structural allele is expressed according to the developmental program characteristic of the species from which it is derived. This provides strong evidence for a cis acting control element.