Figure 3.

Confocal Images Showing the Spatial Localization Patterns of the (+)-Strand of PSTVd That Are Suggestive of Various Stages of Nucleolus-Bound Trafficking of the RNA from the Nucleoplasm.

Serial images of the same cells are presented in the supplemental data online. At stage 1 (S1), the viroid RNA is localized only in the nucleoplasm, as indicated by the nonoverlapping of PSTVd and U3 signals. At S2, there is concentration of the viroid RNA as a nucleoplasmic ring around the nucleolus. At S3, a ring of concentrated RNA appears within the nucleolus. At S4, the RNA is fully within the nucleolus. The diagrams at bottom summarize these patterns. The percentages of cells showing each RNA localization pattern are shown in parentheses. Bars = 2 μm.