Fig. 2

miRNA and siRNA biogenesis. In the nucleus the transcribed Pri-miRNA are converted by DROSHA in Pre-miRNA. Then they are translocated in the cytoplasm by Exportin 5. In the cytoplasm, DICER cleaves the Pre-miRNA in miRNA duplex and then the RISC complex selects the guide strand with consequent RNA target repression. Exogenous dsRNAs are converted in the cytoplasm in siRNA by DICER. Then siRNA is loaded in the RISC complex and, after the cleavage of the passenger strand, the guide strand determines mRNA degradation