Nematic order in cellular tissues: a standardized framework and anomalous defect dynamics

Rapport Preprint Nematic order in cellular tissues: a standardized framework and anomalous defect dynamics eng 2026-04-22 author Rembert Nicolas 0009-0003-5479-1063 University of Geneva; 409058 Biochimie groupe 5 (CHIB5) author Dedenon Mathieu 0000-0002-3028-7984 University of Geneva; 973147 Biochimie (groupe 10) (CHIB10) author Roux Aurélien 0000-0002-6088-0711 University of Geneva; 716946 Département de biochimie (CHIBI) author Dessalles Claire 0000-0002-4554-754X CNRS 983631 10.64898/2026.04.22.719598 http://biorxiv.org/lookup/doi/10.64898/2026.04.22.719598 <p>Cellular monolayers often exhibit orientational order, with nematic alignment of cell shape and cytoskeletal structures governing tissue-scale collective dynamics. Despite extensive studies, a unified analysis framework for characterizing active nematics in living systems remains partial, and key discrepancies with theory persist. Here, we present a systematic and comparative analysis of nematic order and tissue flow dynamics across twelve distinct cell types. We quantify the impact of analysis parameters and provide data-driven guidelines to improve reproducibility and cross-study comparability. Across all nematic systems, we uncover remarkably consistent static properties, supporting the universality of nematic behavior in living tissues. By combining orientation-field analysis with velocity-field measurements and numerical simulations, we show that all examined systems display contractile active nematic signatures, with characteristic flow structures around topological defects. However, direct tracking of individual defects reveals subdiffusive dynamics, in stark contrast with the superdiffusive, self-propelled motion predicted by the hydrodynamic theory of active nematics. Our results establish a standardized framework for nematic analysis in biological systems and highlight fundamental limitations of current active nematic models in describing defect dynamics in living tissues.</p> Dewey 540 Dewey 500.2 39 Département de biochimie 144 37 Département de physique théorique 133 false 769 Groupe Roux 1402 Groupe Kruse ef07a7e6-64aa-4713-a89c-6c9ea939d8df Preprint Public 2026.04.22.719598v1.full.pdf 16999280 application/pdf CC BY-NC-ND-4.0 6865ca5adbc390bc3aa3db2eb2849caf2efa193dce38a7a390b8c43a8d5b22e7 openAccess Faculté des sciences / Section de chimie et biochimie / Département de biochimie Faculté des sciences / Section de physique / Département de physique théorique

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Nematic order in cellular tissues: a standardized framework and anomalous defect dynamics				2026	14	16

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Rembert, Nicolas