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The Initiation of Cytoplasmic Streaming and Locomotion by Mechanochemical Instability
Student-Run Research Seminar| Speaker: | Hongtao Xue, UC Davis |
| Location: | 2112 MSB |
| Start time: | Tue, May 7 2019, 12:30PM |
Physarum Polycephalum is a multinucleated slime mold that forms fast moving amoebae. The cytoplasmic streaming inside the cell drives locomotion, and the net motion of physarum results from the coordination of spatiotemporal organization of oscillating contractions, intracellular fluid flow, and the adhesive interactions with the substrate.
In cell of small size (≤ 100μm), the cytoplasm does not stream and the cell does not crawl, and therefore the cell remains round in shape and stationary. However, instability emerges in larger cell (> 100μm). The cytoplasmic streaming develops asymmetric intracellular flows that cause a pressure-driven protrusion and periodically extend the front of the cell, leading to directional locomotion.
Our work investigates how this kind of emergent symmetry breaking phenomenon initiates and behaves in large cells. We developed a model of active, viscoelastic gel inside the cell to understand the emergence coordination, simulating the asymmetric intracellular flows that are observed in large micro plasmodia, and analyzing the condition for the small cell to remain in stationary.
By comparing the simulation with the experimental data, we approximate the critical value of the parameters, and how these values affect the mechanochemical pattern formation in the locomotion of Physarum Polycephalum.
There will be pizza.