Cell behavior and actomyosin organization in Dictyostelium during substrate exploration

Area of Science:

• Cell Biology
• Cytoskeletal Dynamics
• Cell Motility

Background:

• Understanding cell behavior and cytoskeletal dynamics is crucial for cell motility research.
• Dictyostelium discoideum serves as a model organism for studying cellular processes.

Purpose of the Study:

• To quantitatively analyze the behavior of Dictyostelium amebae upon contact with a glass interface.
• To correlate cellular behavior with the organization of filamentous actin (F-actin) and myosin-II.

Main Methods:

• Computer-assisted analysis using the "Dynamic Morphology System" for cell behavior.
• Fluorescence microscopy and the "agar-overlay method" for F-actin and myosin-II localization.
• Simultaneous observation of cell dynamics and cytoskeletal components in the same cell.

Main Results:

• Dictyostelium amebae display varied responses to a glass interface: crossing, reversing, migrating along, or remaining stationary.
• Cells project lamellipodia and pseudopodia, with pseudopodia exhibiting substrate exploration motions.
• F-actin localizes to lamellipodia and pseudopodia; myosin-II forms a transient lattice at lamellipodia bases.
• Evidence suggests a dorsal-to-ventral sequence in lamellipodia formation and substrate contact.

Conclusions:

• Dictyostelium amoebae demonstrate substrate exploration behavior.
• Cellular behavior is dynamically coupled to actomyosin cytoskeleton reorganization.
• The study provides insights into the polarity of motile and sensory cellular structures.