CRISPR-Cas9 (Clustered Regularly Interspaced Short Palindromic Repeats-Cas9 endonuclease), a Nascent and Promising Technology for Genetic Editing in Mammalian Cells

Genome-editing technologies refer to those systems that have been used to induce changes or modification such as adding or deleting nucleotides on DNA strands. Zinc Finger Nucleases (ZFNs), Transcription Activator-like Effector Nucleases (TALENs), and Clustered Regularly Interspaced Short Palindromic Repeats-Cas9 endonuclease (CRISPR-Cas9) are three common genome editing systems that have their own specific properties, advantages, and disadvantages. The main article “A Genome-wide CRISPR Screen in Primary Immune Cells to Dissect Regulatory Networks” was given by my supervisor Dr Ron Shigeta and by utilizing the Pubmed database, this data is gathered. Parnas and his colleagues showed the efficiency of CRISPR-Cas9 system for finding new regulatory genes in the tumor necrosis factor-alpha (TNF-a) induction pathway. CRISPR-Cas9 is introduced as the most advanced method, because Cas9 can generate break in both strands of DNA with the help of only one sgRNA. Moreover, one Cas9 can cooperate with multiple sgRNAs and break DNA at multiple sites simultaneously and sgRNAs production just needs to design and synthesis 20 nucleotides which have complementary sequence with our target on DNA. Several innovative achievements have been gained by CRISPR-Cas9 technology, for example, the manipulation and modification of the Trypanosoma cruzi (T. cruzi) genome, identification of essential genes for West Nile Virus-induced cell death, and its therapeutic approach for individual with Duchenne muscular dystrophy (DMD). In this manuscript, we evaluate how often CRISPR has been successful, while assessing its specificity and sensitivity for finding regulatory genes. Finally, we discuss what factors or strategies could be utilized to improve its efficacy as a gene editing tool.