@article{21015,
  abstract     = {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.},
  author       = {Mishra, Nikhil and Li, Yuting I and Hannezo, Edouard B and Heisenberg, Carl-Philipp J},
  issn         = {1745-2481},
  journal      = {Nature Physics},
  pages        = {139--150},
  publisher    = {Springer Nature},
  title        = {{Geometry-driven asymmetric cell divisions pattern cell cycles and zygotic genome activation in the zebrafish embryo}},
  doi          = {10.1038/s41567-025-03122-1},
  volume       = {22},
  year         = {2026},
}

@article{20708,
  abstract     = {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.},
  author       = {Martinet, Quentin and Li, Yuting I and Aubret, A. and Hannezo, Edouard B and Palacci, Jérémie A},
  issn         = {2160-3308},
  journal      = {Physical Review X},
  number       = {4},
  publisher    = {American Physical Society},
  title        = {{Emergent dynamics of active elastic microbeams}},
  doi          = {10.1103/rjk2-q2wh},
  volume       = {15},
  year         = {2025},
}