We all know DNA is the hereditary material that makes the protein and gives the individualistic traits to all living organisms. Most traits are wanted and useful, but there are traits that are undesirable and create problems. For example, it would be good to have edible oils with higher ratio of good fatty acids to bad fatty acids. How about eliminating the genes that cause cancer and other deadly diseases? And how about timber trees that don’t flower early, instead grow bigger girth and produce better timber? These are possible if we can knock-out or silence the unwanted genes to prevent them from expressing themselves and producing the unwanted proteins and traits. This is what is known as gene silencing.
Gene silencing is part of genetic modification and is a very useful technique in developing new crop varieties, and has tremendous potential in controlling diseases in humans and animals. Gene silencing simply means switching off or turning down the activity of any undesired gene. Just like DNA, RNA is also made of nucleic acids and is like a courier that delivers the gene’s instruction to make a protein. To silence or turn off a gene’s activity, a mechanism is activated to interfere with the RNA, so the gene’s instruction is never transmitted and the protein is never made. Thus, the gene has been silenced. Because gene silencing involves in the interfering with the RNA activity, it is also known as RNA interference (RNAi).
Scientists are consistently proving that diseases start at gene level and is caused because of malfunctioning of gene expression. With gene silencing, it is possible to shut down a gene and make mutant genes to behave normally. So, turning off the gene that causes cancer is a possibility. Gene silencing too offers tremendous help in drug development. Since this mechanism switches off the activity of only a targeted gene, it is possible to determine the precise function of that gene. This helps in the identification of a target in human cells and is poised to revolutionize drug development.
In the agriculture sector too, gene silencing is an important step in the quest to develop better plants – plants that are able to resist diseases and pests, and plants with improved nutritional qualities.
By Mahaletchumy Arujanan