Strategies for mitochondrial gene editing

Abstract

Graphical abstract

Elucidation of the conformational dynamics and assembly of Argonaute–RNA complexes by distinct yet coordinated actions of the supplementary microRNA

“…Our study illuminated the structural basis of pairing pattern and miRNA lengths’ effect on target RNA recognition, providing insights on control of pairing patterns and miRNA lengths on the design of miRNA mimics and anti-miRNAs. For the potential engineering of AGO proteins as gene silencing and even editing tools [85] , our study may provide a useful guidance to tune AGO proteins for new gene regulation tools.…”

Leigh Syndrome: A Tale of Two Genomes

“…Since mutations in mtDNA contribute to mitochondrial disorders, editing these mutant DNA shift the proportions of mutant to healthy DNA, thereby, reducing the burden of the disease. Currently, restriction endonucleases (RE), zinc finger nuclease (ZFN), transcription activator-like effector nuclease (TALEN), and CRISPR/Cas9 technology are widely used editing tools for this purpose ( Greenfield et al, 2017 ; Reddy et al, 2020 ; Yang et al, 2021 ). The RE, Smal which is usually used for diagnosis of NARP and LS because of its ability to recognize the DNA sequence in the pathogenic variant of the m.8993T > G mutation was modified to eliminate this mutant mtDNA.…”

“…Although a lot of these techniques have been readily adapted to editing the nuclear genome, slight modifications have to be made to target them to mitochondria to modify mtDNA ( Hussain et al, 2021 ). For instance, while CRISPR/Cas9 has been adopted for base editing in the nuclear genome, it has been challenging to do the same with the mitochondrial genome because of the difficulty associated with the delivery of guide RNA into the mitochondria ( Greenfield et al, 2017 ; Hussain et al, 2021 ; Yang et al, 2021 ). However, a CRISPR-free technology involving the use of bacterial cytidine deaminase toxin has been recently developed for use in mitochondrial base editing ( Mok et al, 2020 ).…”

Challenges Facing CRISPR/Cas9-Based Genome Editing in Plants

“…Notably, sgRNA import into these organelles, which are surrounded by a double-membrane envelope, is highly challenging due to strong electrochemical potential ( Glass et al, 2018 ). Although RNA import of unmodified sgRNAs and mitochondrial genome editing via CRISPR/Cas9 has been reported in human cells, the results are controversial ( Jo et al, 2015 ; Gammage et al, 2018 ; Yang et al, 2021 ), underscoring the need for methods that facilitate the transfer of sgRNAs into mitochondria/chloroplasts ( Figure 1 ). Recently, two groups have reported the delivery of nucleic acids into mitochondria or chloroplasts using physical transfection and have shown the integration of exogenous DNA into the organellar genomes.…”