Can Designer Indels Be Tailored by Gene Editing?

Abstract

Genome editing with engineered nucleases (GEENs) introduce site-specific DNA double-strand breaks (DSBs) and repairs DSBs via nonhomologous end-joining (NHEJ) pathways that eventually create indels (insertions/ deletions) in a genome. Whether the features of indels resulting from gene editing could be customized is asked. A review of the literature reveals how gene editing technologies via NHEJ pathways impact gene editing. The survey consolidates a body of literature that suggests that the type (insertion, deletion, and complex) and the approximate length of indel edits can be somewhat customized with different GEENs and by manipulating the expression of key NHEJ genes. Structural data suggest that binding of GEENsto DNA may interfere with binding of key components of DNA repair complexes, favoring either classical-or alternative-NHEJ. The hypotheses have some limitations, but if validated, will enable scientists to better control indel makeup, holding promise for basic science and clinical applications of gene editing. Also see the video abstract here https://youtu.be/vTkJtUsLi3w

Advances in Genome Editing and Application to the Generation of Genetically Modified Rat Models

“…CRISPR-Cas9 has a repair profile closer to the environmental DSB's one compared to other nucleases with a high frequency of insertions of one nucleotide (Trimidal et al, 2019) and mainly repairs using out-of-frame indels (>70%) and microhomologies (Guo et al, 2018;Taheri-Ghahfarokhi et al, 2018).…”

Robust Transcriptional Regulatory Response Upon Blocking NHEJ

“…Our earlier in silico analysis showed that the gene editing enzymes likely interfere with binding of key components of DNA repair complexes and may alter the preference for C-NHEJ or A-NHEJ 10 . Although XRCC4 and MRE-11 are well studied NHEJ complex proteins, we investigated changes in cellular responses when both C-NHEJ and A-NHEJ are blocked by targeting these proteins.…”