What is the primary role of small interfering RNAs (siRNAs)?

The primary role of small interfering RNAs (siRNAs) is to interfere with the translation of mRNA. siRNAs are a class of double-stranded RNA molecules, typically 20-25 nucleotides in length, that can bind to complementary mRNA sequences. Once integrated into the RNA-induced silencing complex (RISC), siRNAs guide the complex to their target mRNA, leading to its degradation or inhibition of translation. This process is a crucial aspect of gene regulation and post-transcriptional silencing.

By facilitating the degradation of specific mRNAs, siRNAs effectively reduce the expression of genes, playing a vital role in cellular processes such as development, defense against viral infections, and maintenance of genome stability. Their function is particularly important in the context of RNA interference (RNAi), a natural mechanism that cells use to regulate gene expression.