OCTOBER 2022LIFE SCIENCES REVIEW8IN MY OPINIONBy Mark Behlke, CSO, Integrated DNA TechnologiesCRISPR Transforming Genome EditingFunctional genomics is the discipline that investigates function of genes through use of synthetic oligonucleotides or longer nucleic acids in living cells in ways that alter the genome or changes gene expression. Tools include antisense oligonucleotides (ASOs), RNA interference, splice-switching oligonucleotides (SSOs), and genome editing. Even though genome editing methods have existed for years, it has caught the trend recently due to the emergence of Clustered Regularly Interspaced Short Palindromic Repeat (CRISPR). The traditional methods of genome editing include zinc-finger nucleases, TALENs, and megaTALS. These older technologies required protein engineering for every different target and scientists had to create a new nuclease everytime they changed the target site, which could take six months of work. But in CRISPR, the protein component stays the same and only the guide RNA (gRNA) changes, which can be mass produced. Consequently, thousands of sites can be simultaneously monitored and changed as desired. This new method has considerably reduced the inconvenience and the time lag associated with site changes. The barrier to working with genome editing technology has been vastly reduced and has opened up new possibilities towards correcting human ailments through gene therapy.A genome editing experiment with CRISPR requires the presence of both the Cas9 nuclease and a gRNA in the cell. In bacteria, where CRISPR naturally occurs, the gRNA is comprised of two separate RNAs that anneal to form an active complex, a short crRNA (that contains a 20 base target-specific domain) and a longer tracrRNA (that directs Mark BehlkeREVOLUTIONIZINGGENOMEEDITING WITH CRISPR
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