Distribution of multiple centrospheres determines migration of BHK syncitia

After fusion of BHK cells with polyethylene glycol, the resulting syncitia contained in 77% of the cases multiple microtubule organizing centers (MTOCs), which were aggregated into a common centrosphere. Based on the observation of phagokinetic tracks, we found that the syncitia were able to locomote if the MTOCs aggregated into a common centrosphere cluster, and the clustered centrospheres were excluded from the cluster of nuclei of the syncitium. The results suggest that each individual pair of one nucleus and one centrosphere contributes, in a process of vectorial addition, its individual polarity to the polarity of the syncitium. Thus the widely accepted idea that the centrosphere is involved in the determination of cell polarity can be generalized beyond the case of single cells.