To effectively perform their functions, biological structures must allow dynamics and turnover of their constituent parts while retaining their mechanical integrity. For example, cell-cell junctions must be dynamic to allow tissue reorganization and the microtubule cytoskeleton must be able to reorganize itself, all while retaining core mechanical and structural features. What are the underlying principles for building such structures? Here, I focus on the mitotic spindle, the microtubule machine-based that delivers chromosomes to two daughter cells during cell division. The accuracy and robustness of its function are essential to health, since mistakes in cell division can lead to cancer, birth defects, and miscarriage. While we have identified many of the molecules essential to spindle function, we do not understand how larger scale mechanical properties emerge.
For example, while we know that microtubule bundles are important structural modules in the spindle, we do not know how the cell builds these bundles or how it holds onto them specifically. In part, this is because of the difficulty of exerting controlled mechanical perturbations inside live cells. By combining confocal imaging, laser ablation, quantitative analysis, and molecular perturbations, we probe how the spindle builds microtubule bundles that attach chromosomes to the spindle, and how it maintains their robust attachment in both space and time. We find that the cell has mechanisms to prevent, detect, and repair damage to chromosome attachment. Together, these mechanisms provide mechanical redundancy and isolation well suited to ensuring accurate chromosome segregation despite dynamic spindle forces and structures
Location: RB101, CVM, NC State University
Time: Sept 26, 2018/ 4-5PM