Fusion of human erythrocytes induced by Sendai virus: freeze-fracture aspects.

Analysis of the freeze-fracture morphology of human erythrocytes during Sendai virus-induced fusion indicates that it occurs in several spots, with the formation of membrane-bound cytoplasmic connexions. Radial expansion of these connexions causes the formation of a polymorphic network of membrane tubules with a lumen continuous with the external space. Our results are best explained assuming that the viral envelopes do not necessarily participate directly in inter-membrane fusion but, instead, indirectly through conditioning and modification of the erythrocyte membranes by viral membrane components.