Speaker
Description
How do cells physically divide? Successful mitosis requires coordinated cortical dynamics that mechanically drive cell morphological changes in space and time. Yet, the field lacks a unified, quantitative description of such physical processes due to limitations in existing methodologies. Here, we present live-cell membrane tension measurements during mitosis in mouse embryonic stem cells. Through our previous work we have established that, given the membrane-to-cortex attachments, plasma membranes and actin cortex operate as an integrated system, where membrane tension readily reflects the underlying cortical dynamics. Hence, via live cell membrane tether assays using optical tweezers, we can monitor mitotic tension dynamics and simultaneously probe at multiple locations around the cell as it rounds up, elongates, furrows, and divides. Our data reveal unexpected tension profiles at the equator and poles, challenging prevailing assumptions and offering quantitative comparisons of detailed dynamics throughout mitosis. These findings pave ways for a comprehensive mechanical diagram of cell division and raise new questions about how mitosis is mechanistically regulated by physical parameters, many of which await to be explored by novel biophysical approaches.
