--- OA_place: publisher OA_type: hybrid PlanS_conform: '1' _id: '21015' abstract: - lang: eng text: Early embryo geometry is one of the most invariant species-specific traits, yet its role in ensuring developmental reproducibility and robustness remains underexplored. Here we show that in zebrafish, the geometry of the fertilized egg—specifically its curvature and volume—serves as a critical initial condition triggering a cascade of events that influence development. The embryo geometry guides patterned asymmetric cell divisions in the blastoderm, generating radial gradients of cell volume and nucleocytoplasmic ratio. These gradients generate mitotic phase waves, with the nucleocytoplasmic ratio determining individual cell cycle periods independently of other cells. We demonstrate that reducing cell autonomy reshapes these waves, emphasizing the instructive role of geometry-derived volume patterns in setting the intrinsic period of the cell cycle oscillator. In addition to organizing cell cycles, early embryo geometry spatially patterns zygotic genome activation at the midblastula transition, a key step in establishing embryonic autonomy. Disrupting the embryo shape alters the zygotic genome activation pattern and causes ectopic germ layer specification, underscoring the developmental significance of geometry. Together, our findings reveal a symmetry-breaking function of early embryo geometry in coordinating cell cycle and transcriptional patterning. acknowledged_ssus: - _id: PreCl - _id: Bio - _id: ScienComp - _id: LifeSc acknowledgement: We thank N. Petridou (EMBL) for sharing results before publication. N.M. was supported by funding from the European Union’s Horizon 2020 programme under the Marie Skłodowska-Curie COFUND Actions ISTplus grant agreement number 754411. Y.I.L. acknowledges funding from the European Union’s Horizon 2020 research and innovation programme under the Marie Skłodowska-Curie grant agreement number 101034413. The research was supported by funding to C.-P.H. from the NOMIS Foundation, Project ID 1.844. We would like to thank past and present members of the Heisenberg and Hannezo groups for discussions, particularly S. Shamipour, V. Doddihal, M. Jovic, N. Hino, F. N. Arslan, R. Kobylinska and C. Camelo for feedback on the draft manuscript. This research was supported by the Scientific Service Units (SSU) of Institute of Science and Technology Austria through resources provided by the Aquatics Facility, Imaging & Optics Facility (IOF), Scientific Computing (SciComp) facility and Lab Support Facility (LSF). Open access funding provided by Institute of Science and Technology (IST Austria). article_processing_charge: Yes (via OA deal) article_type: original author: - first_name: Nikhil full_name: Mishra, Nikhil id: C4D70E82-1081-11EA-B3ED-9A4C3DDC885E last_name: Mishra orcid: 0000-0002-6425-5788 - first_name: Yuting I full_name: Li, Yuting I id: ee7a5ca8-8b71-11ed-b662-b3341c05b7eb last_name: Li - first_name: Edouard B full_name: Hannezo, Edouard B id: 3A9DB764-F248-11E8-B48F-1D18A9856A87 last_name: Hannezo orcid: 0000-0001-6005-1561 - first_name: Carl-Philipp J full_name: Heisenberg, Carl-Philipp J id: 39427864-F248-11E8-B48F-1D18A9856A87 last_name: Heisenberg orcid: 0000-0002-0912-4566 citation: ama: Mishra N, Li YI, Hannezo EB, Heisenberg C-PJ. Geometry-driven asymmetric cell divisions pattern cell cycles and zygotic genome activation in the zebrafish embryo. Nature Physics. 2026;22:139-150. doi:10.1038/s41567-025-03122-1 apa: Mishra, N., Li, Y. I., Hannezo, E. B., & Heisenberg, C.-P. J. (2026). Geometry-driven asymmetric cell divisions pattern cell cycles and zygotic genome activation in the zebrafish embryo. Nature Physics. Springer Nature. https://doi.org/10.1038/s41567-025-03122-1 chicago: Mishra, Nikhil, Yuting I Li, Edouard B Hannezo, and Carl-Philipp J Heisenberg. “Geometry-Driven Asymmetric Cell Divisions Pattern Cell Cycles and Zygotic Genome Activation in the Zebrafish Embryo.” Nature Physics. Springer Nature, 2026. https://doi.org/10.1038/s41567-025-03122-1. ieee: N. Mishra, Y. I. Li, E. B. Hannezo, and C.-P. J. Heisenberg, “Geometry-driven asymmetric cell divisions pattern cell cycles and zygotic genome activation in the zebrafish embryo,” Nature Physics, vol. 22. Springer Nature, pp. 139–150, 2026. ista: Mishra N, Li YI, Hannezo EB, Heisenberg C-PJ. 2026. Geometry-driven asymmetric cell divisions pattern cell cycles and zygotic genome activation in the zebrafish embryo. Nature Physics. 22, 139–150. mla: Mishra, Nikhil, et al. “Geometry-Driven Asymmetric Cell Divisions Pattern Cell Cycles and Zygotic Genome Activation in the Zebrafish Embryo.” Nature Physics, vol. 22, Springer Nature, 2026, pp. 139–50, doi:10.1038/s41567-025-03122-1. short: N. Mishra, Y.I. Li, E.B. Hannezo, C.-P.J. Heisenberg, Nature Physics 22 (2026) 139–150. corr_author: '1' date_created: 2026-01-20T10:12:19Z date_published: 2026-01-05T00:00:00Z date_updated: 2026-04-28T12:55:30Z day: '05' ddc: - '570' department: - _id: EdHa - _id: CaHe doi: 10.1038/s41567-025-03122-1 ec_funded: 1 external_id: oaworkid: - W7118187193 file: - access_level: open_access checksum: 0ab7ac2fbcb61a364dba57152db64ed7 content_type: application/pdf creator: dernst date_created: 2026-01-21T08:21:11Z date_updated: 2026-01-21T08:21:11Z file_id: '21026' file_name: 2026_NaturePhysics_Mishra.pdf file_size: 7335694 relation: main_file success: 1 file_date_updated: 2026-01-21T08:21:11Z has_accepted_license: '1' intvolume: ' 22' language: - iso: eng month: '01' oa: 1 oa_version: Published Version oaworkid: 1 page: 139-150 project: - _id: 260C2330-B435-11E9-9278-68D0E5697425 call_identifier: H2020 grant_number: '754411' name: ISTplus - Postdoctoral Fellowships - _id: fc2ed2f7-9c52-11eb-aca3-c01059dda49c call_identifier: H2020 grant_number: '101034413' name: 'IST-BRIDGE: International postdoctoral program' - _id: 917c023a-16d5-11f0-9cad-eb5cafc52090 name: Cytoplasmic self-organization into cell-like compartments as a common guiding principle in early animal development publication: Nature Physics publication_identifier: eissn: - 1745-2481 issn: - 1745-2473 issnl: - ' 1745-2473' publication_status: published publisher: Springer Nature quality_controlled: '1' related_material: link: - description: News on ISTA website relation: research_data url: https://ista.ac.at/en/news/geometry-shapes-life/ scopus_import: '1' status: public title: Geometry-driven asymmetric cell divisions pattern cell cycles and zygotic genome activation in the zebrafish embryo tmp: image: /images/cc_by.png legal_code_url: https://creativecommons.org/licenses/by/4.0/legalcode name: Creative Commons Attribution 4.0 International Public License (CC-BY 4.0) short: CC BY (4.0) type: journal_article user_id: ba8df636-2132-11f1-aed0-ed93e2281fdd volume: 22 year: '2026' ... --- APC_amount: 4695,11 EUR DOAJ_listed: '1' OA_place: publisher OA_type: gold PlanS_conform: '1' _id: '20708' abstract: - lang: eng text: In equilibrium, the physical properties of matter are set by the interactions between the constituents. In contrast, the energy input of the individual components controls the behavior of synthetic or living active matter. Great progress has been made in understanding the emergent phenomena in active fluids, though their inability to resist shear forces hinders their practical use. This motivates the exploration of active solids as shape-shifting materials, yet, we lack controlled synthetic systems to devise active solids with unconventional properties. Here we build active elastic beams from dozens of active colloids and unveil complex emergent behaviors such as self-oscillations or persistent rotations. Developing tensile tests at the microscale, we show that the active beams are ultrasoft materials, with large (nonequilibrium) fluctuations. Combining experiments, theory, and stochastic inference, we show that the dynamics of the active beams can be mapped on different phase transitions which are tuned by boundary conditions. More quantitatively, we assess all relevant parameters by independent measurements or first-principles calculations, and find that our theoretical description agrees with the experimental observations. Our results demonstrate that the simple addition of activity to an elastic beam unveils novel physics and can inspire design strategies for active solids and functional microscopic machines. acknowledgement: The authors thank Andela Saric, Christoph Zechner, and Paul Robin for helpful discussions. J. P. acknowledges support by ERC grant (VULCAN, 101086998) and U.S. ARO under Award No. W911NF2310008. Y. I. L. acknowledges funding from the European Union’s Horizon 2020 research and innovation programme under the Marie Skłodowska-Curie Grant Agreement No. 101034413. article_number: '041017' article_processing_charge: Yes article_type: original arxiv: 1 author: - first_name: Quentin full_name: Martinet, Quentin id: b37485a8-d343-11eb-a0e9-df8c484ef8ab last_name: Martinet orcid: 0000-0002-2916-6632 - first_name: Yuting I full_name: Li, Yuting I id: ee7a5ca8-8b71-11ed-b662-b3341c05b7eb last_name: Li - first_name: A. full_name: Aubret, A. last_name: Aubret - first_name: Edouard B full_name: Hannezo, Edouard B id: 3A9DB764-F248-11E8-B48F-1D18A9856A87 last_name: Hannezo orcid: 0000-0001-6005-1561 - first_name: Jérémie A full_name: Palacci, Jérémie A id: 8fb92548-2b22-11eb-b7c1-a3f0d08d7c7d last_name: Palacci orcid: 0000-0002-7253-9465 citation: ama: Martinet Q, Li YI, Aubret A, Hannezo EB, Palacci JA. Emergent dynamics of active elastic microbeams. Physical Review X. 2025;15(4). doi:10.1103/rjk2-q2wh apa: Martinet, Q., Li, Y. I., Aubret, A., Hannezo, E. B., & Palacci, J. A. (2025). Emergent dynamics of active elastic microbeams. Physical Review X. American Physical Society. https://doi.org/10.1103/rjk2-q2wh chicago: Martinet, Quentin, Yuting I Li, A. Aubret, Edouard B Hannezo, and Jérémie A Palacci. “Emergent Dynamics of Active Elastic Microbeams.” Physical Review X. American Physical Society, 2025. https://doi.org/10.1103/rjk2-q2wh. ieee: Q. Martinet, Y. I. Li, A. Aubret, E. B. Hannezo, and J. A. Palacci, “Emergent dynamics of active elastic microbeams,” Physical Review X, vol. 15, no. 4. American Physical Society, 2025. ista: Martinet Q, Li YI, Aubret A, Hannezo EB, Palacci JA. 2025. Emergent dynamics of active elastic microbeams. Physical Review X. 15(4), 041017. mla: Martinet, Quentin, et al. “Emergent Dynamics of Active Elastic Microbeams.” Physical Review X, vol. 15, no. 4, 041017, American Physical Society, 2025, doi:10.1103/rjk2-q2wh. short: Q. Martinet, Y.I. Li, A. Aubret, E.B. Hannezo, J.A. Palacci, Physical Review X 15 (2025). corr_author: '1' date_created: 2025-11-30T23:02:08Z date_published: 2025-10-31T00:00:00Z date_updated: 2026-05-20T08:58:06Z day: '31' ddc: - '530' department: - _id: EdHa - _id: JePa doi: 10.1103/rjk2-q2wh ec_funded: 1 external_id: arxiv: - '2508.20642' file: - access_level: open_access checksum: bb64ea9f2c400205fd89e9bdd15cc850 content_type: application/pdf creator: dernst date_created: 2025-12-01T07:30:00Z date_updated: 2025-12-01T07:30:00Z file_id: '20714' file_name: 2025_PhysicalReviewX_Martinet.pdf file_size: 5902259 relation: main_file success: 1 file_date_updated: 2025-12-01T07:30:00Z has_accepted_license: '1' intvolume: ' 15' issue: '4' language: - iso: eng month: '10' oa: 1 oa_version: Published Version project: - _id: bdac72da-d553-11ed-ba76-eae56e802b74 grant_number: '101086998' name: 'VULCAN: matter, powered from within' - _id: fc2ed2f7-9c52-11eb-aca3-c01059dda49c call_identifier: H2020 grant_number: '101034413' name: 'IST-BRIDGE: International postdoctoral program' publication: Physical Review X publication_identifier: eissn: - 2160-3308 publication_status: published publisher: American Physical Society quality_controlled: '1' scopus_import: '1' status: public title: Emergent dynamics of active elastic microbeams tmp: image: /images/cc_by.png legal_code_url: https://creativecommons.org/licenses/by/4.0/legalcode name: Creative Commons Attribution 4.0 International Public License (CC-BY 4.0) short: CC BY (4.0) type: journal_article user_id: 2DF688A6-F248-11E8-B48F-1D18A9856A87 volume: 15 year: '2025' ...