Organization of the Enhancer of split (E(spl)C) locus is diagramed and select genes analyzed in this study are indicated with a “check mark”. Delta induced E(spl) expression was determined with a previously described co-culture assay (Delwig and Rand, 2008). Briefly, S2 cells stably expressing the Notch ligand Delta (Dl-S2 cells) or control S2 parent cells lacking the ligand were cultured as a monolayer then stabilized through brief fixation. C6 cells, which express Notch endogenously, but not the Delta ligand, were then co-cultured with either the fixed Dl-S2 cells or control S2 cells. E(spl) gene expression was measured via qRT-PCR. Data represent the fold change in E(spl) expression in C6 cells due to Delta exposure, Error bars indicate standard deviation. (n=6 (m2, m3, m7, mδ) to 12 (mβ and mγ) independent experimental determinations, * = p<0.01 by Student’s t-test).