Abstract
During development, the alcohol dehydrogenase genes of Drosophila melanogaster and D. affinidisjuncta are expressed in similar, yet distinct, tissue- and stage-specific patterns. Transcripts from both of these genes arise from two promoters (distal and proximal) that also display tissue and stage specificity. We used P-element-mediated transformation to introduce the D. affinidisjuncta Adh gene into the germ line of D. melanogaster. We show that the D. affinidisjuncta Adh gene is expressed at comparable overall levels in both species and that the tissue- and stage-specific expression for this gene (including promoter utilization) is similar in the donor and the host species. However, in some details, the expression of the D. affinidisjuncta gene in D. melanogaster resembles the host pattern, and one novel tissue-specific expression phenotype is displayed by transformants. In general, our results suggest that there has been strong conservation of cis- and trans-acting regulatory factors since the divergence of the two species but that this conservation has not been perfect.
