Question

Compare and contrast three small rna pathways?

Answer 1

Three small rna pathway includes siRNA, miRNA and piRNA .

siRNA- siRNA is most common and popular method used for gene knock down. In this technique, double stranded synthetic RNA is instriduced in the cell for the degradation of mRNA. siRNA have two strand, sense and antisense. When they are introduced into a cell, antisense strande can get cobined with RISC or RNA indiced silencing complex. This complex next bind with the mRNA according to sequence complimentarity and degrades the specific mRNA. As a result the expression of that partcular gene get silenced.

miRNA- they are small non coding RNA sequence which can posttranscriptionally regulate gene expression. miRNAs are found to get bound at the 3'UTR part of a specific mRNA. and further repress the gene expression by targeting and destabilizing the mRNA. As a particular mRNA shows partial complementary sequence wiht specific miRNA, thus a miRNA can reduce the espression of several mRNA.

piRNA- piwi interacting proteins are also non coding RNA found in animal cells. They are able to for RNA/ protein complex in the presence of piwi protein. They are mainly responsible for the gene silecing of retrotraposons in germ lines.through posttranscriptional modification or by epigenetic mechanism.