Within each nucleus, ~2 meters worth of DNA are compacted and intricately organized to facilitate transcription of specific genes in a tightly controlled spatio-temporal manner. However, visualizing how the DNA, specific regulatory elements encoded within it, transcription factors, and transcription are spatially organized in the crowded nuclear environment has remained a challenge.

We previously developed Chromatin Expansion Microscopy (ChromExM) to overcome some of these challenges. This method improves the optical resolution of standard microscopes by physically enlarging developing embryos after embedding them in a series of swellable hydrogels. ChromExM has allowed us to peer into the nanoscale organization inside of individual nuclei and visualize how transcription is turned on in developing embryos.

Ongoing work in the lab will investigate how nuclear organization changes during early development as cells begin to take on unique identities to better understand the fundamental relationship between chromatin structure and function.