FIG. 2.

Intracellular distribution of plus-strand viral RNA in protoplasts infected with CPMV RNA. Protoplasts were collected at the indicated time points after infection with CPMV RNA1 and RNA2 (CPMV), CPMV RNA1 (RNA1), or water (mock) and hybridized with a fluorescein-RNA probe that recognized plus-strand CPMV RNA1. Fluorescent signals were visualized by confocal microscopy measuring optical sections with a focal depth of 1 μm. (A) At 12 hpi, viral RNA was localized in multiple small bodies dispersed over the cytoplasm. (C and E) At 16 hpi, viral RNA was observed in one or several large, amorphous bodies of fluorescence located in the center of protoplasts infected with CPMV (C) or with CPMV RNA1 alone (E). (B and D) Background fluorescence was evaluated in mock-infected protoplasts observed with identical settings at 12 hpi (B) and 16 hpi (D). Bars, 10 μm.