@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{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},
}