Analysis of the Upstream Regulatory Region of the Enhancer of Split m7 gene in Drosophila

The Notch pathway is one of the vital signaling pathways used during Drosophila development. Present in many organisms and extensively studied in D. melanogaster, this pathway serves to transduce signals between neighboring developing cells and inhibits neuronal differentiation by lateral inhibition. The primary targets of Notch are the Enhancer of split (E(spl)) genes. Although the upstream regulatory regions of the E(spl) genes contain biding sites for Suppressor of Hairless, Proneural, and E(spl) proteins, their expression patterns are not identical. There is a hidden complexity in the regulatory regions of these genes that may help explain the conservation of the overall organization of the E(spl) complex between different species of Drosophila. We are interested in determining what is responsible for this variation in expression, and have investigated these genes using different approaches. First, using the upstream regulatory sequence of D. melanogaster and D. pseudoobscura as reference sequences, we compared the upstream regions of the E(spl) m7 gene to D. simulans, D. sechellia, D. yakuba, D. erecta, D. ananassae, D. persimilis, D. grimshawi, D. virilis, and D. mojavensis using BLAT (Kent 2002) and EvoPrinter (Odenwald et al. 2005) applications. Second, we isolated and sequenced part of the regulatory region of D. pseudoobscura m7 to confirm previous published results and gain more insight on the functionality of the region. The differences and similarities in upstream sequences of the E(spl) genes are being used as a tool to help further determine if functions of these genes are conserved. This approach will give insight into which regulatory sites are essential to proper Drosophila development after millions of years of species divergence