Facilitating genome function understanding using genome editing dependent bioimaging techniques

Genomic DNA is highly folded and is stored in the nucleus. In multicellular organisms, genomic DNA exhibits cell type-specific higher-order structures, including specific enhancer–promoter interactions, which have recently been shown to be relevant for cell type-specific regulation of gene expression. However, when the distances between specific enhancers and promoters were measured, cell-to-cell heterogeneity was unexpectedly large and, in some cases, did not correlate with the transcriptional state. These phenomena can be revealed by simultaneously visualizing specific genomic regions and the biological phenomena of interest. In this mini-review, I introduce methodologies for visualizing specific genomic DNA regions and provide detailed examples of how these techniques are being used to elucidate the mechanisms of transcriptional regulation.