Tissue Stiffness Controls How Signals Spread in Developing Embryos
In a series of new studies, EMBL researchers have uncovered a direct link between the physical properties of a tissue and the biochemical signals that guide development.
The team demonstrated that tissue rigidity in zebrafish embryos is directly regulated by cell-cell adhesion, not cell density. This marks a significant shift in understanding how physical forces shape the earliest stages of life.
Increasing cell-cell adhesion causes tissue to transition from fluid-like to solid-like, which can trap signaling molecules like Nodal morphogen.
This trapped Nodal limits its own diffusion, confining developmental signals to specific regions and influencing critical decisions about cell identity. The findings suggest tissues are not just passive scaffolds but active participants in signal distribution.
The research reveals a dynamic feedback loop: Nodal signaling regulates cell-cell adhesion, which in turn affects tissue rigidity and signal localization. This crosstalk creates robust boundaries for developmental compartments.
Methods
The team employed a powerful combination of quantitative measurements, theoretical modeling, advanced live microscopy, and molecular bioengineering on zebrafish embryos. Optogenetic and genetic tools were used to precisely manipulate cell adhesion and density in real time.
Significance
The findings indicate that tissue material properties actively influence biochemical signaling during embryogenesis, directly linking physical and molecular processes. This interplay is proposed as a fundamental mechanism for compartmentalizing developmental signals.
Collaborators
The studies were conducted in collaboration with labs at The Francis Crick Institute (UK) and the University of Graz (Austria). The results appear in Nature Physics and Nature Cell Biology.