THE DROSOPHILA DCREB-A GENE IS REQUIRED FOR DORSAL VENTRAL PATTERNINGOF THE LARVAL CUTICLE/

We report on the characterization of the first loss-of-function mutati on in a Drosophila CREB gene, dCREB-A. In the epidermis, dCREB-A is re quired for patterning cuticular structures on both dorsal and ventral surfaces since dCREB-A mutant larvae have only lateral structures arou nd the entire circumference of each segment. Based on results from epi stasis tests with known dorsal/ventral patterning genes, we propose th at dCREB-A encodes a transcription factor that functions near the end of both the DPP- and SPI-signaling cascades to translate the correspon ding extracellular signals into changes in gene expression. The latera lizing phenotype of dCREB-A mutants reveals a much broader function fo r CREB proteins than previously thought.