Separate DNA sequences are required for normal female and ecdysone-induced male expression of Drosophila melanogaster yolk protein 1.

Drosophila melanogaster flies were transformed with a yp1-Adh fusion gene with 890 bp of yp1 5' flanking sequence. In an Adh- background these flies show a stage, tissue and sex-specific pattern of alcohol dehydrogenase (ADH) activity characteristic of yolk protein genes. ADH activity is not present in dsxD/dsx pseudomales indicating that this fragment contains sites where the dsx gene product exerts its effect. Transformed male flies do not exhibit ADH activity when injected with 20-hydroxyecdysone while synthesis of native yolk proteins is induced. Thus the hormone inducibility and sex regulation have been separated in this construct.