Galvanotactic directionality of cell groups depends on group size

Area of Science:

• Cell Biology
• Biophysics
• Developmental Biology

Background:

• Galvanotaxis is directional cell migration in response to electric fields (EFs), crucial for wound healing and development.
• Individual fish keratocyte cells migrate cathodally in EFs, but PI3K inhibition reverses this to anodally.
• Large cell groups, regardless of PI3K status, migrate cathodally, contrasting with individual cell behavior.

Purpose of the Study:

• To investigate how cell group size and PI3K inhibition affect galvanotaxis.
• To elucidate the mechanisms governing collective cell migration in electric fields.
• To develop and validate a computational model explaining observed group migration patterns.

Main Methods:

• Experimental observation of fish keratocyte cell group migration in electric fields.
• Pharmacological inhibition of PI3-kinase (PI3K) to modulate cell behavior.
• Computational modeling of cell migration dynamics within groups.

Main Results:

• Small uninhibited cell groups migrate cathodally, while small PI3K-inhibited groups migrate anodally.
• Migration speed is higher in smaller groups and in uninhibited groups compared to PI3K-inhibited groups of similar size.
• Large groups exhibit minimal shape changes, whereas small groups deform significantly, losing lamellipodia at rear edges.

Conclusions:

• Cells within group interiors and at edges interpret directional EF signals differently.
• Interior cells are consistently directed cathodally, while edge cells mimic individual cell behavior.
• Group galvanotaxis direction is determined by a balance between interior and edge cell responses, influenced by PI3K status and group size.