Photo: Svilen Milev
CRISPR stands for Clustered Regularly Interspaced Short Palindromic Repeats. These short palindromic repeats within DNA were discovered in bacteria at the end of the 80's of the previous century, while the functions of these sequences have not been known yet. Some 20 years later, Jennifer Doudna of the University of California discovered the fact that the said palindromic repeats perform the role of immune system in bacteria. After having been infected with a virus, a given bacterial cell uses CRISPR ? as cooperating with Cas9 protein ? to split the viral DNA and, finally, to deactivate the virus itself. Scientists have quickly realised that such a capability to cut out specific DNA sequences may be used to eliminate specific genes in animals.
Obviously, biotechnology knows related solutions, such as zinc finger nucleases that may be used to remove specific fragments of genomic DNA. However, no large-scale modification is possible to perform easily with this method applied ? this is where the advantage of CRISPR arises from.When juxtaposed against alternative methods, the system is definitely more effective, while it also is a lot easier to control it. It is composed of two short RNA fragments: one matching the target DNA region and the other one forming a bond with Cas9 protein. A research conducted by a group of Harvard researchers has proven that the efficiency of removal of target genes by CRISPR ranges from 51 and 79%. For comparison, alternative methods only prove efficient in the case of 34% of attempts, and so at their maximum capability.
Currently, there are works conducted on the simultaneous monitoring of many genes with the use of CRISPR. It will make it possible to capture their engagement in various biological reactions.