Shape mode analysis exposes movement patterns in biology: flagella and flatworms as case studies

Area of Science:

• Biophysics
• Computational Biology
• Developmental Biology

Background:

• Describing complex biological shapes and their dynamic changes is challenging.
• Understanding the relationship between shape and function is crucial in biology.

Purpose of the Study:

• To introduce shape mode analysis as a technique for describing complex biological shapes and their dynamics.
• To demonstrate the application of shape mode analysis in characterizing flagellar beating and flatworm locomotion.

Main Methods:

• Shape mode analysis utilizing principal component analysis.
• Analysis of undulatory bending waves in flagella.
• Characterization of non-convex boundary outlines of gliding flatworms.

Main Results:

• Reconstruction of the limit cycle of flagellar oscillations, accounting for angular data periodicity.
• Identification of stereotypic body postures in flatworms linked to distinct locomotion mechanisms.
• Discrimination of different flatworm species based on shape mode analysis, despite motion-induced variability.

Conclusions:

• Shape mode analysis provides a concise method to characterize complex biological shape dynamics using a few time-varying shape scores.
• The technique is versatile, applicable to diverse biological systems like flagella and flatworms.
• Shape mode analysis aids in understanding locomotion mechanisms and species differentiation.