SISENIKOTYC

Cytokinesis in unattached cells, growing as singlets in suspension, is expected to be fundamentally different from adherent cells growing in tissues and tissue-like structures. Lacking biomechanical cues from neighboring cells and surfaces, cell-autonomous cytokinesis is probably better represented by unattached cells. Yet, the current model of mammalian cell division is virtually based on adherent cells, probably due to real visual limitations associated with spheroidal cells in motion. Motivated by this notion, we developed optical flow cytometry approaches for monitoring cytokinesis progression of lymphoblastoid cells. The method, in combination with a targeted screen of small-molecule inhibitors of potential regulators of cytokinesis termination, paved the way to the discovery of ‘Cytokinesis Reversal’ and the mechanism underlying this previously unknown phenomenon. Our findings also highlight an unappreciated means of polyploidy, with relevance to normal and malignant conditions.