Precise base editing without unintended indels in human cells and mouse primary myoblasts

Abstract

Base editors are powerful tools for making precise single-nucleotide changes in the genome. However, they can lead to unintended insertions and deletions at the target sites, which is a significant limitation for clinical applications. In this study, we aimed to eliminate unwanted indels at the target sites caused by various evolved base editors. Accordingly, we applied dead Cas9 instead of nickase Cas9 in the base editors to induce accurate substitutions without indels. Additionally, we tested the use of chromatin-modulating peptides in the base editors to improve nucleotide conversion efficiency. We found that using both dead Cas9 and chromatin-modulating peptides in base editing improved the nucleotide substitution efficiency without unintended indel mutations at the desired target sites in human cell lines and mouse primary myoblasts. Furthermore, the proposed scheme had fewer off-target effects than conventional base editors at the DNA level. These results indicate that the suggested approach is promising for the development of more accurate and safer base editing techniques for use in clinical applications. Researchers have found a method to enhance the precision of gene editing (manipulation of genes), lowering the probability of unwanted genetic changes. The research, directed by D.E.Y and K.K, reviewed the implementation of an enzyme system named CRISPR/Cas9, capable of being programmed to target certain genes in living organisms. Nevertheless, the researchers detected an issue: the enzyme occasionally led to unexpected insertions or removals in the DNA sequences at the target locations. To rectify this, the group substituted a component of the enzyme system with a 'dead' version that couldn't alter DNA, and introduced chromatin-modulating peptide domains (protein parts that influence genetic material). This strategy eradicated unwanted genetic changes while preserving high editing effectiveness. This progress could contribute to safer and more exact gene editing in clinical and biological exploration. This summary was initially drafted using artificial intelligence, then revised and fact-checked by the author.