Effects of PCV2 ORF expression on porcine mature miRNA levels in PK15 cells. A. Venn diagram showing overlap of PCV2 ORF-regulated miRNAs. Upward and downward arrows indicate up-regulation and down-regulation of miRNAs, respectively. Values listed in parentheses indicate the total number of miRNAs differentially regulated by each ORF, compared to parental PK15 cells. B. Splinted ligation analysis of the steady-state levels of mature miRNAs indicated. A representative image from three independent experiments is shown, and parental and empty vector-harboring cells served as controls. Up- or down-regulation of each miRNA by the corresponding ORF(s) is indicated in parentheses. The 5.8S rRNA served as a loading control. C. Quantification of miRNA expression levels from the splinted ligation analysis depicted in B. The levels of miRNAs in parental cells were set to 1, and all error bars represent the mean ± SEM from three independent experiments. **P < 0.01, ***P < 0.001 by one-way ANOVA with the Dunnett’s multiple-comparison test.