FIGURE 7.

The effect of overexpression of RNase H1 on ActD-induced nucleolar fragmentation in HeLa cells. (A) Western blot was used to detect the efficiency of the RNase H1 overexpression plasmid. NC represents samples transfected with empty plasmids. Over-RNase H1 represents samples transfected with pcDNA3.0-RNase H1. (B) ChIP analysis of R-loops at the rDNA regions in HeLa cells after transfection with RNase H1 overexpression plasmid. The y-axis indicates the ratio of the relative quantities of rDNA in the experimental group HeLa cells to the relative quantities of rDNA in control group HeLa cells. The x-axis indicates different regions of rDNA amplicons. Relative values were normalized to the input. Each experiment was repeated three times and the average values are shown with the SD. (C) Percentages of interphase nuclei with more than three fragmented nucleoli after treatment with or without ActD for 24 h. Number of evaluated nuclei in each group was 300. (D) Nucleoli were detected by indirect immunofluorescence staining with an antibody against fibrillarin. Scale bar = 3 μm. Each experiment was repeated three times and the average values are shown with the SD. Data are expressed as *P < 0.05, **P < 0.01, and ***P < 0.001, measured by the t-test.