From local resynchronization to global pattern recovery in the zebrafish segmentation clock.

Area of Science:

• Developmental biology
• Systems biology
• Biophysics

Background:

• The vertebrate segmentation clock relies on Delta-Notch signaling for synchronized gene expression and proper segment formation.
• The role of tissue deformation in complementing cell-cell signaling for segmentation patterning remains unclear.

Purpose of the Study:

• To investigate how tissue deformation influences pattern recovery in the zebrafish segmentation clock after disruption of signaling.
• To develop a theoretical model integrating tissue mechanics with cellular oscillators.

Main Methods:

• Experimental manipulation of Notch inhibition in zebrafish embryos to observe segment recovery.
• Development of a computational model combining coupled oscillators with tissue mechanics.
• Analysis of gene expression patterns and cell advection during segment formation.

Main Results:

• Removing Notch inhibition led to intermingled normal and defective segments, not uniform recovery.
• The new theoretical model successfully captured these intermingled patterns.
• Tissue elongation and cell advection patterns explained the observed recovery dynamics.

Conclusions:

• Segmental pattern recovery involves both rapid local cell synchronization and slower, large-scale tissue morphogenesis.
• Tissue deformation and cell advection are crucial factors in the vertebrate segmentation clock's patterning process.
• A combined approach of theory and experiment provides a comprehensive understanding of developmental patterning.