Mir Laboratory Research Overview

Gene expression is regulated by a complex choreography of highly dynamic events, including the binding of transcription factors to non-coding regulatory regions of the genome, regulation of chromatin topology, and the assembly of large macromolecular complexes, all of which occur in the crowded nuclear environment.

Our understanding of these dynamic processes has largely been driven by approaches that provide population averaged and static snapshots that have delivered remarkable insights, but they are inherently ill suited for elucidating processes that vary greatly in space and time. Comprehending the myriad mechanisms at play in regulating gene expression and the role of nuclear organization in this regulation requires technological and theoretical approaches that bridge spatial scales from molecular to organismal and temporal scales from milliseconds to days.

We develop and utilize high-resolution light-sheet microscopy methods, which allows us to probe this vast range of spatial and temporal scales within living embryos (so far working with mouse models, Drosophila, and C. elegans). For example, we can acquire:

• High-speed volumetric data to quantify chromatin dynamics (Video 1)
• Multi-color datasets to study the interaction and distribution of protein domains associated with gene activation or repression as cell fates are determined in young embryos (Video 2)
• And use single molecule localization techniques to quantify the kinetics of individual transcription factors as they whizz around the nucleoplasm searching for and binding to their genomic targets (Video 3).