Two pair-rule responsive enhancers regulate wingless transcription in the Drosophila blastoderm embryo.

Background: While many developmentally relevant enhancers act in a modular fashion, there is growing evidence for nonadditive interactions between distinct cis-regulatory enhancers. We investigated if nonautonomous enhancer interactions underlie transcription regulation of the Drosophila segment polarity gene, wingless.

Results: We identified two wg enhancers active at the blastoderm stage: wg 3613u, located from -3.