article published yes Silvia Caballero Mancebo author 2F1E1758-F248-11E8-B48F-1D18A9856A870000-0002-5223-3346 Rushikesh Shinde author Madison Bolger-Munro author 516F03FA-93A3-11EA-A7C5-D6BE3DDC885E0000-0002-8176-4824 Matilda Peruzzo author 3F920B30-F248-11E8-B48F-1D18A9856A870000-0002-3415-4628 Gregory Szep author 4BFB7762-F248-11E8-B48F-1D18A9856A87 Irene Steccari author 2705C766-9FE2-11EA-B224-C6773DDC885E David Labrousse Arias author CD573DF4-9ED3-11E9-9D77-3223E6697425 Vanessa Zheden author 39C5A68A-F248-11E8-B48F-1D18A9856A870000-0002-9438-4783 Jack Merrin author 4515C308-F248-11E8-B48F-1D18A9856A870000-0001-5145-4609 Andrew Callan-Jones author Raphaël Voituriez author Carl-Philipp J Heisenberg author 39427864-F248-11E8-B48F-1D18A9856A870000-0002-0912-4566 CaHe department JoFi department MiSi department EM-Fac department NanoFab department Control of embryonic cleavage pattern project Contraction and flow of the actin cell cortex have emerged as a common principle by which cells reorganize their cytoplasm and take shape. However, how these cortical flows interact with adjacent cytoplasmic components, changing their form and localization, and how this affects cytoplasmic organization and cell shape remains unclear. Here we show that in ascidian oocytes, the cooperative activities of cortical actomyosin flows and deformation of the adjacent mitochondria-rich myoplasm drive oocyte cytoplasmic reorganization and shape changes following fertilization. We show that vegetal-directed cortical actomyosin flows, established upon oocyte fertilization, lead to both the accumulation of cortical actin at the vegetal pole of the zygote and compression and local buckling of the adjacent elastic solid-like myoplasm layer due to friction forces generated at their interface. Once cortical flows have ceased, the multiple myoplasm buckles resolve into one larger buckle, which again drives the formation of the contraction pole—a protuberance of the zygote’s vegetal pole where maternal mRNAs accumulate. Thus, our findings reveal a mechanism where cortical actomyosin network flows determine cytoplasmic reorganization and cell shape by deforming adjacent cytoplasmic components through friction forces. https://research-explorer.ista.ac.at/download/14846/17267/2024_NaturePhysics_CaballeroMancebo.pdf application/pdfno Springer Nature2024 eng 1745-2473 1745-2481 38370025 00113888080000510.1038/s41567-023-02302-1 20310-321 https://ista.ac.at/en/news/stranger-than-friction-a-force-initiating-life/ Caballero Mancebo S, Shinde R, Bolger-Munro M, et al. Friction forces determine cytoplasmic reorganization and shape changes of ascidian oocytes upon fertilization. <i>Nature Physics</i>. 2024;20:310-321. doi:<a href="https://doi.org/10.1038/s41567-023-02302-1">10.1038/s41567-023-02302-1</a> Caballero Mancebo S, Shinde R, Bolger-Munro M, Peruzzo M, Szep G, Steccari I, Labrousse Arias D, Zheden V, Merrin J, Callan-Jones A, Voituriez R, Heisenberg C-PJ. 2024. Friction forces determine cytoplasmic reorganization and shape changes of ascidian oocytes upon fertilization. Nature Physics. 20, 310–321. Caballero Mancebo, Silvia, et al. “Friction Forces Determine Cytoplasmic Reorganization and Shape Changes of Ascidian Oocytes upon Fertilization.” <i>Nature Physics</i>, vol. 20, Springer Nature, 2024, pp. 310–21, doi:<a href="https://doi.org/10.1038/s41567-023-02302-1">10.1038/s41567-023-02302-1</a>. Caballero Mancebo, Silvia, Rushikesh Shinde, Madison Bolger-Munro, Matilda Peruzzo, Gregory Szep, Irene Steccari, David Labrousse Arias, et al. “Friction Forces Determine Cytoplasmic Reorganization and Shape Changes of Ascidian Oocytes upon Fertilization.” <i>Nature Physics</i>. Springer Nature, 2024. <a href="https://doi.org/10.1038/s41567-023-02302-1">https://doi.org/10.1038/s41567-023-02302-1</a>. S. Caballero Mancebo <i>et al.</i>, “Friction forces determine cytoplasmic reorganization and shape changes of ascidian oocytes upon fertilization,” <i>Nature Physics</i>, vol. 20. Springer Nature, pp. 310–321, 2024. Caballero Mancebo, S., Shinde, R., Bolger-Munro, M., Peruzzo, M., Szep, G., Steccari, I., … Heisenberg, C.-P. J. (2024). Friction forces determine cytoplasmic reorganization and shape changes of ascidian oocytes upon fertilization. <i>Nature Physics</i>. Springer Nature. <a href="https://doi.org/10.1038/s41567-023-02302-1">https://doi.org/10.1038/s41567-023-02302-1</a> S. Caballero Mancebo, R. Shinde, M. Bolger-Munro, M. Peruzzo, G. Szep, I. Steccari, D. Labrousse Arias, V. Zheden, J. Merrin, A. Callan-Jones, R. Voituriez, C.-P.J. Heisenberg, Nature Physics 20 (2024) 310–321. 148462024-01-21T23:00:57Z2025-09-04T11:48:28Z