Glassy dynamics in three-dimensional embryonic tissues.
Many biological tissues are viscoelastic, behaving as elastic solids on short timescales and fluids on long timescales. This collective mechanical behaviour enables and helps to guide pattern formation and tissue layering. Here, we investigate the mechanical properties of three-dimensional tissue explants from zebrafish embryos by analysing individual cell tracks and macroscopic mechanical response. We find that the cell dynamics inside the tissue exhibit features of supercooled fluids, including subdiffusive trajectories and signatures of caging behaviour. We develop a minimal, three-parameter mechanical model for these dynamics, which we calibrate using only information about cell tracks. This model generates predictions about the macroscopic bulk response of the tissue (with no fit parameters) that are verified experimentally, providing a strong validation of the model. The best-fit model parameters indicate that although the tissue is fluid-like, it is close to a glass transition, suggesting that small changes to single-cell parameters could generate a significant change in the viscoelastic properties of the tissue. These results provide a robust framework for quantifying and modelling mechanically driven pattern formation in tissues.
170 Carl Icahn Laboratory, Lewis-Sigler Institute, Princeton University, , Princeton, NJ 08544, USA.
Eva-Maria
EM
Schötz
Marcos
M
Lanio
Jared A
JA
Talbot
M Lisa
ML
Manning
D000818:Animals; D001696:Biomechanical Phenomena; D002450:Cell Communication; D004625:Embryo, Nonmammalian / Q000166:cytology* / Q000648:ultrastructure; D047108:Embryonic Development; D008954:Models, Biological; D017711:Nonlinear Dynamics; D046509:Tissue Culture Techniques; D015027:Zebrafish / Q000196:embryology*
active matter; embryonic development; glassy dynamics; supercooled fluid; tissue modelling; tissue viscoelasticity