About this Research Topic
The CRISPR/Cas9 system has been developed as a robust and versatile platform for manipulating the genomes of a variety of species. The use of CRISPR/Cas9 technology suggests many potential applications, including human gene therapy and animal breeding.
Generally, the CRISPR/Cas9 nuclease is used to cleave target genome DNA to generate site-specific double-strand breaks (DSBs), which can be repaired mainly through two pathways in mammalian cells, namely non-homologous end joining (NHEJ) and homology-directed repair (HDR) pathways. The NHEJ repair pathway can generate uncontrollable insertions or deletions (indels) resulting in loss-of-function of targeted coding genes by open reading frame (ORF) shift. On the other hand, HDR relies on homologous donor DNA to produce targeted gene knock-in, as well as designed precise point or small mutations. Besides, microhomology-mediated end joining (MMEJ), as an alternative non-homologous end joining repair pathway, can also mediate efficient gene knock-in. In addition to the CRISPR/Cas9 system, other CRISPR systems (such as CRISPR/Cpf1) have also been developed and applied for genome editing usage.
Here, we mainly focus on the HDR-based precise genome editing, such as gene correction, point mutation, base editing, designed small insertion and deletion. However, there are still some difficulties during the precise genome editing manipulation, including the low HDR efficiency, the failure of biallelic targeting, and the problem of positive selection as well as the removal of selection markers. Interestingly, it has been recently reported that base editing can be also achieved without DNA cleavage and DSBs by a novel CRISPR-derived technique.
We would like to focus our Research Topic on precise genome editing techniques and their applications in mammals. However, other novel interesting genome editing techniques or relevant significant optimizations and applications can be also considered. Manuscripts we would like to be submitted include:
1. Novel precise genome editing techniques and applications using CRISPR system (such as CRISPR/Cas9 and CRISPR/Cpf1), as well as other nuclease technology (such as TALENs, and gDNA/NgAgo if it does work).
2. Improvements of HDR-based precise genome editing, such as strategies for improving HDR efficiency, enriching or selecting for genome-modified cells and enhancing biallelic targeting.
3. Investigations regarding to HDR donor optimization and selection.
4. Pop in and pop out strategies for marker-free and seamless genome editing.
5. Genomic base editing techniques and applications without DNA cleavage and DSBs.
6. Significant precise genome editing applications for gene therapy.
7. Novel interesting genome editing techniques or significant applications beyond precise genome editing, such as an efficient lncRNA knocking-out strategy.
Keywords: Genome editing, CRISPR, HDR efficiency, Gene correction, Base editing
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