{"record":{"author":{"account_ref":null,"orcid":null},"builds_on":[],"content_schema":"pubphys.content.revision/1","content_sha256":"21fdada7acdb9397249a9a9b55739c1784bf9f9956c17027cda41c3f8aa5dd32","created":"2026-10-03T07:17:57Z","files":[],"origin":{"assisted_by":[],"kind":"seed"},"parents":["5475cf5dc5b1a72283d26dc95dc6e00d7ea4e00096a7c6492e409a1816eeb011"],"salt":"472001da39135798aed3192e7e4f9e25cdec0ea94f58c498c94ea9e0a524128d","schema":"pubphys.record/2","site":"pubphys.com","target":null,"type":"revision"},"content":{"answer_type":"value","assisted_by":[],"external_id":"bio.chromatin-extrusion.in-vivo-kinetics","kind":"well-posed","literature_status":"partially-resolved","n":"1","parents":[],"plain":"Purified cohesin extrudes DNA in a test tube at roughly a thousand base pairs per second. How fast it works inside a crowded nucleus, and how long loops last, has been measured at only a few sites.","posed_since":"","precise":"Measure, genome-wide in living mammalian cells, the cohesin extrusion speed (kb/s), residence time on chromatin, and the fraction of time a CTCF-anchored loop is fully formed, and test whether polymer simulations with these parameters reproduce Hi-C contact maps (contact probability P(s) and domain boundaries) without refitting. Answer: values with uncertainties and the outcome of the consistency test.","problem_ref":null,"references":"","settled_by":"Live-cell imaging of many loci, or time-resolved contact mapping after acute cohesin release, combined with parameter-free polymer simulation.","status_note":"Live imaging of one mouse locus (2022) found the fully looped state present only a few percent of the time; genome-wide in vivo rates remain open.","title":"Speed and lifetime of loop extrusion inside living cells","topic_ref":"8ad1a941274484056fe235f47000030ee6a6486f2d2e01d87c8ec53a250ea12e"},"attested":{"attestation":{"batch":null,"client_id":null,"id_token_sha256":null,"kind":"platform"},"record_hash":"da8e137f7871edae9513baf4903ff7a1fd1cdb2aa8809e0b18796577cc5b71a0","schema":"pubphys.attested/1"},"envelope":{"attested_hash":"514507ac01b1a1c985b8febfb532dadc61810dd0fecbb49c0e0276212891bf56","platform_signature":{"key_id":"c6afc19b31429869751f06879c75cd64ea92654423d15b44be775bf1310a60da","sig":"oW70TYf-zSpwCQgJzDH9rR7j1G0X_jN0yxViyyFy_AhVOfGzUPf6dTja-OTXQo-0jaUlSJnvRZYg3H_KIGBcAw"},"schema":"pubphys.envelope/1"},"record_hash":"da8e137f7871edae9513baf4903ff7a1fd1cdb2aa8809e0b18796577cc5b71a0","leaf_index":741}