Adhesion strength, cell packing density and cell surface buckling in pericellular matrix-mediated tissue cohesion

Area of Science:

• Developmental Biology
• Biophysics
• Cell Biology

Background:

• Cell-cell adhesion is crucial for tissue formation.
• The pericellular matrix influences cell interactions and tissue architecture.
• Xenopus gastrula provides a model for studying early embryonic tissue dynamics.

Purpose of the Study:

• To investigate the role of fibronectin in Xenopus gastrula cell adhesion and tissue organization.
• To understand the physical mechanisms governing cell-cell contact formation and interstitial space.
• To explore the mechanical properties of cell surfaces during tissue development.

Main Methods:

• Fibronectin knockdown via morpholino injection in Xenopus embryos.
• Microscopy techniques to observe cell contacts and tissue morphology.
• Analysis of cell surface mechanics, including buckling and crumpling phenomena.

Main Results:

• Fibronectin knockdown decreased cell contact abundance and packing density without affecting adhesion strength.
• Cell surfaces in gastrula tissues exhibited solid-like behavior (buckling, crumpling).
• These phenomena are explained by pericellular matrix compression and stiffening during contact formation.

Conclusions:

• The pericellular matrix, not adhesion strength, determines interstitial space size in Xenopus gastrula.
• Matrix compression leads to non-adhesive surfaces and mechanical instabilities like buckling.
• An elasto-capillary model explains tissue cohesion based on matrix abundance and cell contractility.