Light controlled cell-fates in embryonic development

During embryonic development, cellular fates are tightly regulated in space and time. Transcription factors (TFs) play a critical role in cell fate determination. However, complex regulatory codes and mechanisms make it challenging to interpret a direct role of TF inputs in gene activity. To overcome these challenges, we have combined light perturbation of TF input, real-time gene output measurements, and Drosophila genetics to build synthetic spatial and temporal gene activity patterns in living fly embryos. In particular, we have built a light delivery platform that allows for flexible light patterns to instruct light-sensitive TFs in space and time. Upon light illumination, TFs translocate to the cytosolic compartment and allow for modulation of nuclear TF concentration and thus downstream gene activity patterns. We are developing a quantitative approach to modulate TF’s input concentration and record transcriptional gene output in real-time to bring a new dimension to the study of transcriptional dynamics in a developing embryo.