[Kinetics and ultrastructure of sheep fibroblast fusion induced by polyethylene glycol. Comparison with endogenous cell fusion induced by Visna virus].

The authors compare the fusion of sheep fibroblasts induced by low multiplicities of infection using visna virus and by high concentrations of polyethylene-glycol. In the case of Visna virus cell fusion is of the endogenous type, while fusion induced by polyethylene-glycol is of the exogenous type. The ultrastructural features are discussed for each type of cell fusion. The main differences between the two systems involve the intracellular microfilaments and Golgi apparatus.