Understanding Spontaneous Cytoskeletal Self-Organization in Cytoplasma Using Reconstituted Mitotic Extracts

The cytoplasm is a highly crowded, organized environment. Within this space, physical and biological phenomena contribute to its organization. However, the origin of this organization is an interesting question - whether these assemblies are spontaneous or self-directed, or are templated by the cell. Cheng and Ferrell, 2019, found cell-like compartments spontaneously appearing in bulk cytosol. These compartments can assemble independent of nuclei, but require the cytoskeleton. Using the same Xenopus laevis egg-based cell-free extract platform, we seek to understand the properties modulating this self-organization. The extract platform allows for direct manipulation of both the chemical and mechanical environment of the system, and also makes high-resolution imaging more accessible. We have established the simultaneous imaging of Cdk-1 mitotic trigger waves with compartments capable of division. Preliminary results show Cdk-1 trigger waves preceding division events, suggesting that the timing of mitotic events is similar in the self-organized compartments. Results also suggest that there is an influence on the geometric shapes of the compartments by the dimensions of the imaging tubes, resulting in shapes that resemble Voronoi diagrams.