DNA Synthesis and Mitosis in Fused Cells

Abstract

When HeLa cells growing in asynchronous culture are fused together by inactivated Sendai virus, synchrony of DNA synthesis and mitosis is rapidly imposed in the resultant multinucleate cells, even though the single cells which fuse to form these multinucleate cells are at different stages of the cell cycle. Some measure of nuclear co-ordination can already be observed within a few hours of cell fusion, and maximal synchrony is achieved within 2 days. By the end of the second day after fusion, asynchronous DNA synthesis or mitosis is rare. In binucleate cells this high order of synchrony is maintained for at least 5 days, but in cells containing greater numbers of nuclei some loss of synchrony begins to appear after the third day. The results indicate that the ability of the multinucleate cell to co-ordinate nuclear events is not impaired by the use of virus to facilitate cell fusion.