[Ultrastructural aspects of the cell fusion induced by Visna virus on sheep choroid plexus cell in culture].

Sheep choroid plexus cells infected with low multiplicities of infection of Visna Virus were stellate and had long and thin processes containing filaments and forming cytoplasmic bridges between adjacent cells. Enlargement of the bridges resulted in the formation of multinucleated cells. Some glycoproteins were clustered on filaments outside the cell. The cytoplasmic changes showed : an intensive protein synthesis; numerous mitochondria closely associated with filaments and some lysosomes and numerous vesicules near the plasma membrane.