Figure 2: Functional stages of gene silencing with dsRNA in cells of insects and viruses. The figure shows steps involved in systemic gene silencing and the molecules involved in them. Exogenous dsRNA is imported into cells (for insects), processed by dicer into small interfering (siRNA) and loaded into RNA induced silencing complex (RISC) with the help of argonaute protein (AGO). This RISC complex targets and degrades specific mRNAs based on siRNA sequence. For viruses perfectly base-paired dsRNA is produced from bidirectional transcription, RNA dependent RNA polymerase (RdRP) action etc. processed by dicer into siRNAs and loaded into AGO containing RISC complex. This siRNA-RISC complex further target homologous mRNAs for translational arrest.