The CRISPR-Cas9 system is a tool for cutting DNA at a specifically targeted location. The technique has already revolutionized gene editing, but scientists are always looking for new possibilities. So what else can CRISPR do?
CRISPR: Gene Editing and Beyond
Since being discovered in a bacteria immune system, CRISPR-Cas9 has been adapted into a powerful tool for genomic research. There're two components to the system: A DNA cutting protein called Cas9 and an RNA molecule known as the Guide RNA. Bond together, they form a Complex that can identify and cut specific sections of DNA.
First, Cas9 has to locate and (bind?) to a common sequence of DNA called a PAM. Once the PAM is bind, the guide RNA unwinds apart the double-helix. The RNA strap is designed to match and bind a particular sequence of DNA. Once it has found a correct sequence, Cas9 can cut the DNA. Its two nuclear (触点) each make a nick leading the double strap break. Although the cell will try to repair this break, the fixing process is error-prone, and often (不可避免地) introduces mutations that disable the gene. This makes CRISPR a great tool for knocking out specific genes.
But making double strap breaks is not all CRISPR can do. Some researchers are deactivating one or both of Cas9's cutting (触点), (附加) new enzymes to the protein. Cas9 can then be used to transport those enzymes to specific DNA sequences. In one example, ... (好难啊!