Expression pattern analysis of 6,300 genomic fragments for cis-regulatory activity in the imaginal discs of Drosophila Melanogater. Aurélie Jory¹, Carlos Estella^1,3, Matt W. Giorgianni^1,4, Matthew Slattery^1,5, Todd R. Laverty², Gerald M. Rubin², Richard S. Mann¹. 1) Department of Biochemistry and Molecular Biophysics, Columbia University Medical Center, 701 W. 168th Street, HHSC 1104, New York, NY 10032, USA; 2) Janelia Farms Research Campus, 19700 Helix Drive, Ashburn, VA 20147, USA; 3) Present address: Departamento de Biología Molecular, and Centro de Biología Molecular Severo Ochoa, Universidad Autónoma de Madrid, Madrid, Spain; 4) Present address: R.M. Bock Laboratories, University of Wisconsin-Madison, 1525 Linden Drive, Madison, WI 53706, USA; 5) Present address: Institute for Genomics and Systems Biology, University of Chicago, 900 E. 57th St. KCBD 10115, Chicago, IL 60637, USA.

   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 around 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. Using this database and new computational and biochemistry results, we will present a deeper analysis of selected cis-regulatory modules (CRMs) involved in the proximo-distal patterning of the leg and antenna discs.