Ultrastructure of cylindrical inclusions induced by viruses of the potato Y group as visualized by freeze-etching

Cylindrical inclusions induced by tobacco etch virus (TEV), potato virus Y (PVY), and turnip mosaic virus (TuMV) were examined by freeze-etch electron microscopy. The inclusion morphology in situ was similar to that previously reported from thin-sectioning studies, thus confirming that viruses in the potato Y group induce inclusions of characteristic morphology. Freeze-etching was also found to be useful for studying substructure. Inclusion subunits were clearly resolved when inclusions induced by TEV and PVY were examined both in situ and in isolated form.