{"paper":{"title":"From Flow to Form: Emergence of the Cytokinetic Ring via Active Cortical Dynamics","license":"http://creativecommons.org/licenses/by/4.0/","headline":"Active cortical flows in a cell model spontaneously form a nematic actomyosin ring at the equator that drives sharp invagination.","cross_cats":["physics.bio-ph"],"primary_cat":"cond-mat.soft","authors_text":"Anirban Sain, Sabyasachi Mukherjee","submitted_at":"2026-04-19T09:47:05Z","abstract_excerpt":"During cell division active flows occur in the cortex, a thin layer of gel like network of acto myosin filaments, beneath the cell surface. The cortical flow and the associated stresses bring about change in the cell shape, in particular a sharp invagination at the mid cell. Using 3D phase field simulation of an active deformable shell, which captures coupled dynamics of cortical velocity and nematic order, we show how a nematic like actomyosin ring spontaneously emerge at the equator and drive sharp invagination. We further demonstrate how different cortical flow patterns, including counter r"},"claims":{"count":4,"items":[{"kind":"strongest_claim","text":"we show how a nematic like actomyosin ring spontaneously emerge at the equator and drive sharp invagination. We further demonstrate how different cortical flow patterns, including counter rotating flows emerge near the division furrow. We show that these flow patterns, often attributed to intrinsic chirality of actomyosin filaments can instead arise from bias in the initial nematic alignment, revealing a memory effect in the system.","source":"verdict.strongest_claim","status":"machine_extracted","claim_id":"C1","attestation":"unclaimed"},{"kind":"weakest_assumption","text":"That the 3D phase field simulation of the active deformable shell accurately captures the real coupled dynamics of cortical velocity and nematic order in living cells, and that the observed behaviors are not artifacts of the model parameters or initial conditions chosen.","source":"verdict.weakest_assumption","status":"machine_extracted","claim_id":"C2","attestation":"unclaimed"},{"kind":"one_line_summary","text":"A 3D simulation of active cortical dynamics reveals spontaneous emergence of a nematic actomyosin ring at the cell equator that drives invagination, with counter-rotating flows resulting from initial alignment bias rather than intrinsic chirality.","source":"verdict.one_line_summary","status":"machine_extracted","claim_id":"C3","attestation":"unclaimed"},{"kind":"headline","text":"Active cortical flows in a cell model spontaneously form a nematic actomyosin ring at the equator that drives sharp invagination.","source":"verdict.pith_extraction.headline","status":"machine_extracted","claim_id":"C4","attestation":"unclaimed"}],"snapshot_sha256":"277eb89961cbd0d0a37d4f84c4621404b8c88839ce87c93a229a83334ad76877"},"source":{"id":"2604.17349","kind":"arxiv","version":2},"verdict":{"id":"9c561705-daff-4659-a879-aedd2bd0720d","model_set":{"reader":"grok-4.3"},"created_at":"2026-05-10T05:45:27.201953Z","strongest_claim":"we show how a nematic like actomyosin ring spontaneously emerge at the equator and drive sharp invagination. We further demonstrate how different cortical flow patterns, including counter rotating flows emerge near the division furrow. We show that these flow patterns, often attributed to intrinsic chirality of actomyosin filaments can instead arise from bias in the initial nematic alignment, revealing a memory effect in the system.","one_line_summary":"A 3D simulation of active cortical dynamics reveals spontaneous emergence of a nematic actomyosin ring at the cell equator that drives invagination, with counter-rotating flows resulting from initial alignment bias rather than intrinsic chirality.","pipeline_version":"pith-pipeline@v0.9.0","weakest_assumption":"That the 3D phase field simulation of the active deformable shell accurately captures the real coupled dynamics of cortical velocity and nematic order in living cells, and that the observed behaviors are not artifacts of the model parameters or initial conditions chosen.","pith_extraction_headline":"Active cortical flows in a cell model spontaneously form a nematic actomyosin ring at the equator that drives sharp invagination."},"integrity":{"clean":true,"summary":{"advisory":0,"critical":0,"by_detector":{},"informational":0},"endpoint":"/pith/2604.17349/integrity.json","findings":[],"available":true,"detectors_run":[],"snapshot_sha256":"c28c3603d3b5d939e8dc4c7e95fa8dfce3d595e45f758748cecf8e644a296938"},"references":{"count":0,"sample":[],"resolved_work":0,"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57","internal_anchors":0},"formal_canon":{"evidence_count":0,"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"author_claims":{"count":0,"strong_count":0,"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"builder_version":"pith-number-builder-2026-05-17-v1"}