In every cell, a set of genes interact with one another (creating “genetic circuits”) to control specific cellular functions. Combinations of these functional modules at the right time and place create emergent behaviors at the multicellular level. My lab is interested in understanding how genetic circuits in individual cells enable dynamic multicellular functions, such as self-organizing into tissues, and how changes in the circuits lead to evolutionary phenotypes. To address this question, we construct genetic circuits and reconstitute multicellular behavior in a petri dish using synthetic biology and bioengineering tools, guided by mathematical models. This bottom-up approach allows us to test the sufficiency of the circuits and understand the design principles by rewiring the circuits. In parallel, we also analyze natural circuits in developing tissues, combining genetic perturbation, quantitative imaging and transcriptomic analysis. Together, we aim to provide a quantitative understanding of development and evolution, as well as new ways to engineer tissues.