Figure 5.

When cells were injected with Tagetin (injection dye as shown in left panels in A), a loss of perinucleolar labeling of the PTB protein is observed (top panels in A). Overexpression of RNase MRP RNA directed by a pol II promoter partially blocks the loss of PNCs in Tagetin-injected cells. The middle panel in the second row (A) shows that a cell expressing MRP RNA maintains a large and irregularly shaped PNC, and the bottom panels show one of the injected cells with a smaller and dot-like PNC (arrow). (B) Quantitative analyses show a smaller percentage of cells losses PNCs compared with those without expression of MRP RNA from a pol II promoter (Figure 3). Bar, 10 μm.