# Narration and storyboard draft: Chromatin Accessibility = Transcriptional Competence

Authored draft, approximately 60–90 seconds; no rendered video claimed.

Open chromatin is a useful signpost for gene regulation. It is not a guarantee that a gene will switch on. Our review examined61primary reports and selected Methods or Results from6original papers. Acute BRG1 and BAF experiments show that remodelers help maintain access and nascent transcription. But those proteins also recruit factors and coactivators, so their necessity does not automatically prove necessity of the measured open state itself. One especially informative zebrafish experiment restored DNA accessibility with a catalytically inactive acetyltransferase without restoring transcription. The active enzyme restored both. Direction also varies: opening can precede developmental activation, while transcription restart and paused polymerase can build or stabilize access in other settings. Consensus helped identify additional studies and organize these comparisons; each important claim was checked against the original source at its recorded access depth. Under HSEFv5.3, the broad necessity claim remains mechanistically plausible with partial support. A decisive next experiment would change accessibility selectively and test the same activating challenge, while preserving the other regulatory machinery.

1. Show the exact claim, grade and confidence.
2. Show selected publication milestones; label experimental systems and clinical endpoints.
3. Contrast the strongest result with its source-specific limitation.
4. End with the boundary experiment and primary-source links.

Use authored schematics; do not depict Consensus meters as causal confidence or reproduce publisher graphics without appropriate permission.