168366 20260204153543.0 doi 10.7554/eLife.93097 sideral 147804 ART-2025-147804 eng Mirza, Waleed Theory of active self-organization of dense nematic structures in the actin cytoskeleton 2025 The actin cytoskeleton is remarkably adaptable and multifunctional. It often organizes into nematic bundles such as contractile rings or stress fibers. However, how a uniform and isotropic actin gel self-organizes into dense nematic bundles is not fully understood. Here, using an active gel model accounting for nematic order and density variations, we identify an active patterning mechanism leading to localized dense nematic structures. Linear stability analysis and nonlinear finite element simulations establish the conditions for nematic bundle self-assembly and how active gel parameters control the architecture, orientation, connectivity, and dynamics of self-organized patterns. Finally, we substantiate with discrete network simulations the main requirements for nematic bundle formation according to our theory, namely increased active tension perpendicular to the nematic direction and generalized active forces conjugate to nematic order. Our work portrays actin gels as reconfigurable active materials with a spontaneous tendency to develop patterns of dense nematic bundles. Access copy available to the general public Unrestricted info:eu-repo/grantAgreement/ES/MICINN/ICJ2018-035270-I info:eu-repo/semantics/openAccess by https://creativecommons.org/licenses/by/4.0/deed.es info:eu-repo/semantics/article info:eu-repo/semantics/publishedVersion De Corato, Marco Universidad de Zaragoza (orcid)0000-0002-9361-4794 Pensalfini, Marco Vilanova, Guillermo Torres-Sánchez, Alejandro Arroyo, Marino 5001 600 Universidad de Zaragoza Dpto. Ciencia Tecnol.Mater.Fl. Área Mecánica de Fluidos 13 (2025), [33 pp.] eLife (Cambridge) eLife 2050-084X 16309594 http://zaguan.unizar.es/record/168366/files/texto_completo.pdf Versión publicada 2404911 http://zaguan.unizar.es/record/168366/files/texto_completo.jpg?subformat=icon icon Versión publicada oai:zaguan.unizar.es:168366 articulos driver 2026-02-04-13:14:36 ARTICLE