Quantitative cell fusion: derivation and application of theoretical models.
Cell fusion experiments were made on ten cell lines representing seven mammalian species, using inactivated Sendai virus. The extent of fusion was determined microscopically and tabulated as frequencies of cell with different numbers of nuclei. Expected distributions were derived theoretically under certain assumptions concerning the fusion process. A random model was assumed according to which the tendency to fuse depends only on the cell size, expressed as the number of nuclei present in the cell. Three distributions were derived, which were referred to as the simple, additive, and multiplicative models. The additive model pertained to fusions made in cell suspensions and the multiplicative one mainly to fusions in fibroblast monolayers.