The frequency and consequences of multipolar mitoses in undifferentiated embryonic stem cells

Abstract

Embryonic stem (ES) cells are pluripotent cells widely used in cell therapy and tissue engineering. However, the broader clinical applications of ES cells are limited by their genomic instability and karyotypic abnormalities. Thus, understanding the mechanisms underlying ES cell karyotypic abnormalities is critical to optimizing their clinical use. In this study, we focused on proliferating human and mouse ES cells undergoing multipolar divisions. Specifically, we analyzed the frequency and outcomes of such divisions using a combination of time-lapse microscopy and cell tracking. This revealed that cells resulting from multipolar divisions were not only viable, but they also frequently underwent subsequent cell divisions. Our novel data also showed that in human and mouse ES cells, multipolar spindles allowed more robust escape from chromosome segregation control mechanisms than bipolar spindles. Considering the frequency of multipolar divisions in proliferating ES cells, it is conceivable that cell division errors underlie ES cell karyotypic instability. Highlights:• Undifferentiated embryonic stem (ES) cells that undergo multipolar divisions are viable and continue to divide. • Polyploid ES cells generated by inhibition of cytokinesis more frequently undergo multipolar division. • Cells undergoing multipolar division escape from spindle assembly checkpoint (SAC) activity faster than bipolar dividing cells.

Geometric Control of Cell Behavior by Biomolecule Nanodistribution

“…Immunocytochemistry analysis was performed as previously described. 66 Briefly, the seeded cells were fixed in 4% paraformaldehyde for 15 min at room temperature. The cells were then permeabilized with 0.1% Triton X-100 detergent and subsequently blocked with 3% bovine serum albumin.…”