Using Drosophila embryos, we show how transcriptional repressors contribute to gene expression dynamics. Image is a snapshot from live RNA-imaging of short-gastrulation enhancer driven reporter output at nuclear cycle 13. This imaging technique presents an improved quantitative tool for live-imaging analysis (MS2-MCP system), to allow assay of spatiotemporal expression dynamics. Nuclear membranes were visualized by Nup-RFP-fluorescence (red), while nascent transcripts in the nucleus by GFP-fluorescence (blue dots). Image by Theodora Koromila, PhD.