Genome engineering with the CRISPR/Cas system

During recent decades, genetic science has dramatically progressed in the manipulation of genetic material and, consequently, the treatment of diseases. Currently, it is well known that genetic engineering is highly capable to create targeted changes in plant and animal genomes to resolve many breeding limitations, develop new traits, and improve effective genome quantity and quality. One of these techniques is CRISPR/Cas technology, discovered and designed by a group of Japanese scientists in ۱۹۸۷, based on editing the gene of the bacterial immune system. Owing to its very high compatibility in different laboratory conditions and the capabilities added through genetic engineering, the system has been introduced as the genome engineering technology at the level of eukaryotic cells. Clustered Regularly Interspaced Short Palindromic Repeats (CRISPR) were first identified in the genome of Escherichia coli as an acquired immune system against bacteriophage invasion and the intrusion of foreign DNA (such as plasmids) into the bacterial cell. Later on, the CRISPR gene families were also identified in all prokaryotes in ۲۰۰۰. The introduction of this technique enabled bioscience researchers to manipulate DNA molecules for the first time to develop novel therapeutic strategies. This system has been widely developed in various plant and animal species for genome editing, gene silencing, control of the transcription process with high specificity, lowering the effect of non-target sequences by double-strand breaks (DSBs) in genomic DNA, and changing the nucleotide sequence of the target gene. Researchers are also trying to achieve a system to treat various diseases by addressing such problems as high specificity, cleavage of non-target loci, transfer to the cell, and launching a suitable repair system. The ever-increasing progress of this technology and the identification of new proteins with more advantages than the existing proteins (e.g., cas۹) promise the treatment of genetic diseases in the future.

Keywords:

Genome modification , gene therapy , CRISPR , genetic engineering , gene editing