article published yes Suyash Naik author 2C0B105C-F248-11E8-B48F-1D18A9856A870000-0001-8421-5508 Yann-Edwin Keta author Kornelija Pranjic-Ferscha author 4362B3C2-F248-11E8-B48F-1D18A9856A87 Edouard B Hannezo author 3A9DB764-F248-11E8-B48F-1D18A9856A870000-0001-6005-1561 Silke Henkes author Carl-Philipp J Heisenberg author 39427864-F248-11E8-B48F-1D18A9856A870000-0002-0912-4566 Bio department CaHe department EdHa department Keratins in epithelial tissue spreading project Nano-Analytics of Cellular Systems project For tissues to spread, they must deform while staying intact. How spreading tissues balance flexibility with integrity is not yet well understood. Here, we show that keratin intermediate filaments adapt tissue mechanical resilience to the stresses arising in epithelial tissues during spreading. By analyzing the expansion of the enveloping cell layer (EVL) over the yolk cell in zebrafish embryos in vivo, we find that keratin network maturation in EVL cells is promoted by stresses building up within the spreading tissue. Through genetic interference and tissue rheology experiments, complemented by a vertex model with mechanochemical feedback, we demonstrate that stress-induced keratin network maturation in the EVL increases tissue viscosity, to prevent tissue rupture. Further, keratins are required in the yolk cell for mechanosensitive actomyosin network contraction and flow, the forces pulling the EVL. These dual mechanosensitive functions of keratins enable a balance between pulling force production and EVL mechanical resilience, ensuring uniform and robust tissue spreading. https://research-explorer.ista.ac.at/download/22608/22609/2026_NatureComm_Naik.pdf application/pdfno Springer Nature2026 eng 2041-1723 4214304810.1038/s41467-026-72366-z 17 https://research-explorer.ista.ac.at/record/20465 S. Naik, Y.-E. Keta, K. Pranjic-Ferscha, E.B. Hannezo, S. Henkes, C.-P.J. Heisenberg, Nature Communications 17 (2026). Naik, Suyash, Yann-Edwin Keta, Kornelija Pranjic-Ferscha, Edouard B Hannezo, Silke Henkes, and Carl-Philipp J Heisenberg. “Keratins Coordinate Tissue Spreading by Balancing Spreading Forces with Tissue Material Properties.” <i>Nature Communications</i>. Springer Nature, 2026. <a href="https://doi.org/10.1038/s41467-026-72366-z">https://doi.org/10.1038/s41467-026-72366-z</a>. Naik S, Keta Y-E, Pranjic-Ferscha K, Hannezo EB, Henkes S, Heisenberg C-PJ. 2026. Keratins coordinate tissue spreading by balancing spreading forces with tissue material properties. Nature Communications. 17, 6499. Naik, Suyash, et al. “Keratins Coordinate Tissue Spreading by Balancing Spreading Forces with Tissue Material Properties.” <i>Nature Communications</i>, vol. 17, 6499, Springer Nature, 2026, doi:<a href="https://doi.org/10.1038/s41467-026-72366-z">10.1038/s41467-026-72366-z</a>. S. Naik, Y.-E. Keta, K. Pranjic-Ferscha, E. B. Hannezo, S. Henkes, and C.-P. J. Heisenberg, “Keratins coordinate tissue spreading by balancing spreading forces with tissue material properties,” <i>Nature Communications</i>, vol. 17. Springer Nature, 2026. Naik, S., Keta, Y.-E., Pranjic-Ferscha, K., Hannezo, E. B., Henkes, S., &#38; Heisenberg, C.-P. J. (2026). Keratins coordinate tissue spreading by balancing spreading forces with tissue material properties. <i>Nature Communications</i>. Springer Nature. <a href="https://doi.org/10.1038/s41467-026-72366-z">https://doi.org/10.1038/s41467-026-72366-z</a> Naik S, Keta Y-E, Pranjic-Ferscha K, Hannezo EB, Henkes S, Heisenberg C-PJ. Keratins coordinate tissue spreading by balancing spreading forces with tissue material properties. <i>Nature Communications</i>. 2026;17. doi:<a href="https://doi.org/10.1038/s41467-026-72366-z">10.1038/s41467-026-72366-z</a> 226082026-07-29T09:10:35Z2026-07-29T10:33:31Z