Long-range transcriptional regulation in the developing Drosophila eye
Differential gene expression is the mechanism by which similar cells express a particular set of genes that lead to a specific cellular outcome. Enhancers play a major role in regulating differential gene expression; they are sequences of regulatory noncoding DNA, almost like an instruction manual, that determine where, when and how much a gene is expressed. Enhancers are often found endogenously at great distances from the genes they regulate, and the mechanism of this long-distance regulation is largely unknown. One specific long-range enhancer is the sparkling enhancer, which drives cone cell specific expression of the dPax-2 gene in Drosophila. The Barolo lab has identified a region of the sparkling enhancer that is only necessary when the enhancer is at a distance from the gene that it regulates; therefore this region was named the Remote Control Element, or RCE. Further experiments studying the RCE will help elucidate the general mechanism of long-range transcriptional regulation.