Model to Link Cell Shape and Polarity with Organogenesis.

Area of Science:

• Developmental biology
• Cellular mechanics
• Biophysics

Background:

• Epithelial sheet morphogenesis is crucial for forming tubular structures like the gut and neural tube.
• Mechanisms such as cell wedging, actomyosin cable formation, and cell intercalation are known to contribute to tube formation.
• The individual sufficiency of these mechanisms in driving the entire sheet-to-tube transition remains unclear.

Purpose of the Study:

• To computationally investigate whether cell wedging or cell intercalation alone can drive the complete transition of a flat cell sheet into a tube.
• To determine if a single mechanism is sufficient for both bending the sheet and elongating the tube.

Main Methods:

• Utilized a physics-based computational model representing epithelial cells as polarized point particles.
• Simulated scenarios focusing on either cell wedging or cell intercalation as the primary driving force.
• Validated model predictions against key features observed in biological systems.

Main Results:

• Demonstrated that cell intercalation alone is sufficient to bend the cell sheet and elongate the tube.
• Showed that cell wedging alone is also sufficient to achieve both sheet bending and tube elongation.
• Found that the combined action of wedging and intercalation enhances the robustness of tube formation.

Conclusions:

• Either cell wedging or intercalation can independently drive the entire process of epithelial tube formation.
• These mechanisms contribute to the bending and elongation phases of morphogenesis.
• The computational model's success in replicating features of Drosophila salivary gland budding, sea urchin gastrulation, and mammalian neurulation supports the broad applicability of the findings.