@article{9316,
  abstract     = {Embryo morphogenesis is impacted by dynamic changes in tissue material properties, which have been proposed to occur via processes akin to phase transitions (PTs). Here, we show that rigidity percolation provides a simple and robust theoretical framework to predict material/structural PTs of embryonic tissues from local cell connectivity. By using percolation theory, combined with directly monitoring dynamic changes in tissue rheology and cell contact mechanics, we demonstrate that the zebrafish blastoderm undergoes a genuine rigidity PT, brought about by a small reduction in adhesion-dependent cell connectivity below a critical value. We quantitatively predict and experimentally verify hallmarks of PTs, including power-law exponents and associated discontinuities of macroscopic observables. Finally, we show that this uniform PT depends on blastoderm cells undergoing meta-synchronous divisions causing random and, consequently, uniform changes in cell connectivity. Collectively, our theoretical and experimental findings reveal the structural basis of material PTs in an organismal context.},
  author       = {Petridou, Nicoletta and Corominas-Murtra, Bernat and Heisenberg, Carl-Philipp J and Hannezo, Edouard B},
  issn         = {1097-4172},
  journal      = {Cell},
  number       = {7},
  pages        = {1914--1928.e19},
  publisher    = {Elsevier},
  title        = {{Rigidity percolation uncovers a structural basis for embryonic tissue phase transitions}},
  doi          = {10.1016/j.cell.2021.02.017},
  volume       = {184},
  year         = {2021},
}

@article{5789,
  abstract     = {Tissue morphogenesis is driven by mechanical forces that elicit changes in cell size, shape and motion. The extent by which forces deform tissues critically depends on the rheological properties of the recipient tissue. Yet, whether and how dynamic changes in tissue rheology affect tissue morphogenesis and how they are regulated within the developing organism remain unclear. Here, we show that blastoderm spreading at the onset of zebrafish morphogenesis relies on a rapid, pronounced and spatially patterned tissue fluidization. Blastoderm fluidization is temporally controlled by mitotic cell rounding-dependent cell–cell contact disassembly during the last rounds of cell cleavages. Moreover, fluidization is spatially restricted to the central blastoderm by local activation of non-canonical Wnt signalling within the blastoderm margin, increasing cell cohesion and thereby counteracting the effect of mitotic rounding on contact disassembly. Overall, our results identify a fluidity transition mediated by loss of cell cohesion as a critical regulator of embryo morphogenesis.},
  author       = {Petridou, Nicoletta and Grigolon, Silvia and Salbreux, Guillaume and Hannezo, Edouard B and Heisenberg, Carl-Philipp J},
  issn         = {1465-7392},
  journal      = {Nature Cell Biology},
  pages        = {169–178},
  publisher    = {Nature Publishing Group},
  title        = {{Fluidization-mediated tissue spreading by mitotic cell rounding and non-canonical Wnt signalling}},
  doi          = {10.1038/s41556-018-0247-4},
  volume       = {21},
  year         = {2019},
}

@article{6980,
  abstract     = {Tissue morphogenesis in multicellular organisms is brought about by spatiotemporal coordination of mechanical and chemical signals. Extensive work on how mechanical forces together with the well‐established morphogen signalling pathways can actively shape living tissues has revealed evolutionary conserved mechanochemical features of embryonic development. More recently, attention has been drawn to the description of tissue material properties and how they can influence certain morphogenetic processes. Interestingly, besides the role of tissue material properties in determining how much tissues deform in response to force application, there is increasing theoretical and experimental evidence, suggesting that tissue material properties can abruptly and drastically change in development. These changes resemble phase transitions, pointing at the intriguing possibility that important morphogenetic processes in development, such as symmetry breaking and self‐organization, might be mediated by tissue phase transitions. In this review, we summarize recent findings on the regulation and role of tissue material properties in the context of the developing embryo. We posit that abrupt changes of tissue rheological properties may have important implications in maintaining the balance between robustness and adaptability during embryonic development.},
  author       = {Petridou, Nicoletta and Heisenberg, Carl-Philipp J},
  issn         = {1460-2075},
  journal      = {The EMBO Journal},
  number       = {20},
  publisher    = {Embo Press},
  title        = {{Tissue rheology in embryonic organization}},
  doi          = {10.15252/embj.2019102497},
  volume       = {38},
  year         = {2019},
}

@article{678,
  abstract     = {The seminal observation that mechanical signals can elicit changes in biochemical signalling within cells, a process commonly termed mechanosensation and mechanotransduction, has revolutionized our understanding of the role of cell mechanics in various fundamental biological processes, such as cell motility, adhesion, proliferation and differentiation. In this Review, we will discuss how the interplay and feedback between mechanical and biochemical signals control tissue morphogenesis and cell fate specification in embryonic development.},
  author       = {Petridou, Nicoletta and Spiro, Zoltan P and Heisenberg, Carl-Philipp J},
  issn         = {1465-7392},
  journal      = {Nature Cell Biology},
  number       = {6},
  pages        = {581 -- 588},
  publisher    = {Nature Publishing Group},
  title        = {{Multiscale force sensing in development}},
  doi          = {10.1038/ncb3524},
  volume       = {19},
  year         = {2017},
}