Nucleome dynamics and histone priming by pioneer transcription factors drive osteoblast differentiation.

Pioneer transcription factor ETS1 primes histone activation and drives 3D genome reorganization during osteoblast differentiation, with B-to-A chromatin shifts pre-marked in pre-osteoblasts.

• Why it matters: Understanding how genome architecture and histone modifications coordinate to regulate osteogenesis can reveal targets for bone regeneration and repair. Despite knowledge of transcriptional changes, the mechanisms linking chromatin dynamics to osteoblast maturation remain unclear.
• What they did: The study used high-throughput 3D genome profiling and histone modification analyses to investigate genome compartment shifts in osteoblasts, identifying ETS1 as a pioneer factor that recruits p300 to prime chromatin before gene activation.
• The result: Findings demonstrate that ETS1-mediated histone priming facilitates large-scale genome reorganization, enabling osteogenic gene expression and providing insights into the epigenetic regulation of bone formation.