Cellular Phase of Chromosome Pulverization Induced by Sendai Virus

Summary

Autoradiographic studies of the chromosome pulverization phenomenon in cultured Chinese hamster cells induced by Sendai virus revealed that the pulverized materials were actually interphasic nuclei affected either during the S or G2 periods. The fusion between cells at these cell phases and those at the mitotic stages promptly led to the pulverization of nuclei derived from the S and G2 phase cells. Furthermore, even if a syncytium was formed by two interphasic cells, it had a potential to present a pulverization figure when one of the two nuclei arrived at the mitotic stage. The existence of asynchrony in the DNA synthesis of the two nuclei in the syncytium was indispensable in this case as well. The intensity of pulverization seemed to depend on the degree of asynchrony in the two nuclei of the same syncytium.