Measurements of Cell Mass Distribution during Cell Division with Quantitative Phase Microscopy

Abstract

Despite much attention to the regulation of genetic material partitioning during cell division, relatively little is known about the partitioning of cell mass, an essential outcome of successful cytokinesis. Recent work suggests that mispartitioning of cellular contents during division may constitute a form of epigenetic memory, however, conventional techniques cannot accurately quantify daughter cell masses. Quantitative phase microscopy, in which the phase shift of light as it passes through and interacts with matter inside a cell is measured, in combination with computer vision techniques, provides a new approach for directlyView Large Image | View Hi-Res Image | Download PowerPoint Slide measuring the masses of hundreds of paired daughter cells and tracking the resultant cell fates. We will show that, across several cell types, approximately one in ten cell divisions results in a highly asymmetric partitioning of mass. Additionally, we have found that specific disruption of acto-myosin activity using small molecule inhibitors leads to a marked increase in the percentage of highly-asymmetric cell divisions. This suggests that sub-cytotoxic concentrations of chemotherapeutics may lead to dramatic variation in cancer cell population mass distributions and potential epigenetic effects on cell function and disease progression.