Enhancers are small regulatory pieces of DNA that control the activity of genes, which eventually determine cellular fates during the development of multicellular organisms. They need to measure the concentrations of various input effector molecules, called transcription factors, and then act over often very long distances along the DNA in order to activate a distantly located gene. In this talk I will present my laboratory's progress on two fundamental physical properties of these enhancers: 1. How do enhancers operate at long distances to instruct gene activity? 2. How do enhancers decode the information of the input transcription factors and then transduce it into a precise output? We use a combination of genome editing, live imaging and statistical mechanics techniques to address these questions in the developing fly embryo. Speaker(s): Thomas Gregor (Princeton University)