siRNAmediated

siRNA-mediated gene silencing is a biological process that utilizes small interfering RNA (siRNA) molecules to regulate gene expression at the post-transcriptional level. This mechanism is a fundamental component of the RNA interference (RNAi) pathway, a conserved cellular defense system found in many organisms, including plants, animals, and fungi. The process begins when double-stranded RNA (dsRNA) is cleaved by an enzyme called Dicer into short siRNA duplexes, typically 21–25 nucleotides in length. One strand of the siRNA, known as the guide strand, is incorporated into the RNA-induced silencing complex (RISC), while the other strand, the passenger strand, is degraded.

The active RISC-siRNA complex then binds to complementary messenger RNA (mRNA) sequences within the cell, leading to the cleavage or translational repression of the target mRNA. This results in the degradation of the mRNA and subsequent reduction of the corresponding protein production, effectively silencing the gene. The specificity of siRNA-mediated silencing is determined by the sequence complementarity between the siRNA guide strand and the target mRNA, allowing precise regulation of gene expression.

This technology has significant applications in both research and therapeutic contexts. In molecular biology, siRNA is widely used as a tool to knock down specific genes, enabling the study of gene function and pathways. In medicine, siRNA-based therapies aim to treat diseases caused by dysfunctional genes, such as certain cancers, viral infections, and genetic disorders. However, challenges remain, including delivery efficiency, off-target effects, and immune responses, which researchers continue to address through advancements in siRNA design and delivery systems.