Spatial Attractors in Aggregation Patterns of Dictyostelium discoideum

Area of Science:

• Cellular Biology
• Biophysics
• Developmental Biology

Background:

• Slime mould Dictyostelium discoideum exhibits self-organized chemotactic cell motion.
• Cellular aggregation is driven by cyclic adenosine monophosphate (cAMP) signaling.
• cAMP signals propagate as spiral or target patterns.

Purpose of the Study:

• To analyze the chemotactic cell motion in Dictyostelium discoideum aggregation patterns.
• To investigate the self-organization mechanisms driven by cAMP signals.
• To characterize cell movement dynamics in spiral and target patterns.

Main Methods:

• Computerized cross-correlation method for analyzing cell motion.
• Streamline calculations to determine probable cell trajectories.
• Observation of cell movement in response to cAMP signals.

Main Results:

• Vortex-like cell rotation observed near spiral wave cores (max velocity 15 μm/min).
• Cell motion and spiral tip rotation occur in opposite directions.
• A spatial limit cycle (radius ≈ 130 μm) defines the spiral core boundary, attracting cells.
• Target patterns induce radial, star-shaped cell motion towards central mounds.

Conclusions:

• Cellular movement in Dictyostelium discoideum is intricately organized by cAMP signaling patterns.
• Spiral waves create a unique attractant boundary leading to cell-free zones.
• Target patterns facilitate direct radial aggregation for mound formation.