SEM observations on Sendai virus-induced fusion of embryonic mouse erythroblasts.

The events of fusion of 11- and 16-day embryonic mouse liver erythroblasts induced by Sendai virus (SV) were followed with the scanning electron microscope (SEM). Erythroid precursors incubated with the virus showed numerous 'pores' on the cell membrane. The cell fusion began with the appearance of a fine 'meshwork' structure between the adjacent cells, followed by a gradual formation of a common cell membrane and terminated with the appearance of polykaryons, in which the nuclei were easily recognized when located in the vicinity of the polykaryon membrane. There was no difference in the process of fusion between erythroblasts at identical and those at different stages of maturation.