title: [Electron microscopic observation of the infectious cycle of Visna virus in sheep choroid plexus cells at temperatures under 37 degrees C].
abstract: Electron microscope study of viral penetration at 4 degrees C shows that viral particles first attach to cells. The attachment sites are invaginations which later fuse to form phagocytic cytoplasmic vacuoles. Some virus particles with altered envelopes can be seen in the cytoplasm. After ten days of incubation at 29 degrees C, filamentous inclusions and mature viral particles are seen in the cytoplasm. The cellular membrane budding process and virus release observed at 37 degrees C have disappeared. When the above preparations are warmed to 37 degrees C, budding is seen, and two kinds of extracellular particles are present, one with a clear center and the other with a dense core (mature virus).
mesh_terms: D000818:Animals; D002478:Cells, Cultured; D002831:Choroid Plexus / Q000382:microbiology*; D008854:Microscopy, Electron; D008954:Models, Biological; D012328:RNA Viruses / Q000254:growth & development*; D012756:Sheep; D013696:Temperature; D014779:Virus Replication; D014790:Visna-maedi virus / Q000254:growth & development*
vernacular_title: Observation en microscopie électronique du cycle infectieux du virus Visna sur cellules de plexus choroïdes de mouton à des températures inférieures à 37 degrees C