How the tooth got its stripes: patterning via strain-cued motility.

Area of Science:

• Biophysics
• Developmental Biology
• Materials Science

Background:

• Cell migration is crucial for tissue development and pattern formation.
• Understanding the physical forces driving collective cell migration is key to developmental biology.

Purpose of the Study:

• To propose and test a biophysical theory where local strain gradients drive collective cell migration patterns.
• To validate this theory by modeling the microstructure formation during amelogenesis (enamel development).

Main Methods:

• Developed a discrete-cell simulation model based on simple rules for cell motion in response to local strain.
• Simulated the behavior of ameloblasts during mouse incisor enamel formation.
• Compared simulation outputs to observed morphological characteristics of dental enamel.

Main Results:

• The model accurately reproduced key features of enamel microstructure, including waviness and decussation patterns.
• The simulation predicted the speed and shape of the 'commencement front' separating migrating and non-migrating ameloblasts.
• The model successfully explained the transition from decussating to non-decussating enamel structures.

Conclusions:

• Collective cell migration patterns can arise from mechanical interactions (local strains) rather than solely chemical signals.
• The proposed biophysical mechanism provides a robust explanation for the complex morphology of developing dental enamel.
• A single adjustable parameter in the model was sufficient to capture diverse microstructural features.