Copyright channelnewsasia
Originally derived from a natural genome-editing system that bacteria use to defend against viruses, scientists have adapted CRISPR-Cas9 into a powerful tool for editing DNA. The technology has been used mainly in blood cancers or paediatric neuromuscular diseases. First, scientists identify the DNA sequence they want to alter. A “guide RNA” is designed and attached to a Cas9 protein. The RNA guides the Cas9 enzyme to the exact spot in the DNA, where the protein then acts as a pair of molecular scissors, snipping out the targeted portion. Once the DNA is cut, the cell will naturally heal by trimming the broken ends and joining them back together. But this repair process can result in an unusable gene. Instead, scientists introduce a separate sequence of template DNA – a blueprint that helps guide the rebuilding process. This can repair a defective gene or even insert a new one. The technique enables scientists to target almost any gene in the genome, including those responsible for diseases. However, the long-term effects of this technology are still being studied.
