Single-cell 3D genome imaging shows super-enhancer hubs are rare, nonspecific, and neither necessary nor sufficient for transcriptional bursting.

Super-enhancer hubs are rare, nonspecific, and neither necessary nor sufficient for transcriptional bursting in mouse embryonic stem cells.

• Why it matters: Understanding the role of 3D genome organization in gene regulation is crucial, as super-enhancer hubs have been proposed to coordinate gene expression, but their actual significance remains unclear.
• What they did: Using multiplexed imaging of hundreds of SEs in thousands of mouse embryonic stem cells, combined with nascent transcription measurements, the study mapped SE positions and their association with transcriptional activity.
• The result: Most SEs are spatially isolated, with rare, promiscuous hubs that are shaped by genomic proximity and nuclear features; disrupting genome organization generally suppresses SE clustering, and hubs only weakly increase transcriptional burst probability, challenging models of SE hub dominance.