A Survey of 6,300 Genomic Fragments for cis-Regulatory Activity in the Imaginal Discs of Drosophila melanogaster

Over 6,000 fragments from the genome of Drosophila melanogaster were analyzed for their ability to drive expression of GAL4 reporter genes in the third-instar larval imaginal discs. About 1,200 reporter genes drove expression in the eye, antenna, leg, wing, haltere, or genital imaginal discs. The patterns ranged from large regions to individual cells. About 75% of the active fragments drove expression in multiple discs; 20% were expressed in ventral, but not dorsal, discs (legs, genital, and antenna), whereas ∼23% were expressed in dorsal but not ventral discs (wing, haltere, and eye). Several patterns, for example, within the leg chordotonal organ, appeared a surprisingly large number of times. Unbiased searches for DNA sequence motifs suggest candidate transcription factors that may regulate enhancers with shared activities. Together, these expression patterns provide a valuable resource to the community and offer a broad overview of how transcriptional regulatory information is distributed in the Drosophila genome. [Display omitted] ► Over 6,000 fragments from the Drosophila genome were analyzed for enhancer ► About 1,200 fragments drove expression of GAL4 in at least one of six imaginal discs ► The lines greatly expand the number of GAL4 drivers available to the community Mann and colleagues provide an overview of the expression patterns of ∼1,200 enhancer-GAL4 reporter genes that are expressed in Drosophila imaginal discs. Analysis of DNA sequence motifs suggests candidate transcription factors that may regulate enhancers with shared activities. These data provide a valuable resource to the Drosophila community and offer a broad overview of how transcriptional regulatory information is distributed in the Drosophila genome.