Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
Review
. 2016 Aug;101(4):213-5.
doi: 10.1136/archdischild-2016-310459. Epub 2016 Apr 8.

What is CRISPR/Cas9?

Melody Redman  1 , Andrew King  2 , Caroline Watson  3 , David King  4
Affiliations
Review

What is CRISPR/Cas9?

Melody Redman et al. Arch Dis Child Educ Pract Ed. 2016 Aug.
No abstract available

Keywords: CRISPR/cas9; children; gene editing; genome engineering.

PubMed Disclaimer

Figures

Figure 1
Figure 1
The CRISPR/Cas9 system. Clustered regularly interspaced palindromic repeats (CRISPR) refers to sequences in the bacterial genome. They afford protection against invading viruses, when combined with a series of CRISPR-associated (Cas) proteins. Cas9, one of the associated proteins, is an endonuclease that cuts both strands of DNA. Cas9 is directed to its target by a section of RNA. This can be synthesised as a single strand called a synthetic single guide RNA (sgRNA); the section of RNA which binds to the genomic DNA is 18–20 nucleotides. In order to cut, a specific sequence of DNA of between 2 and 5 nucleotides (the exact sequence depends upon the bacteria which produces the Cas9) must lie at the 3’ end of the guide RNA: this is called the protospacer adjacent motif (PAM). Repair after the DNA cut may occur via two pathways: non-homologous end joining, typically leading to a random insertion/deletion of DNA, or homology directed repair where a homologous piece of DNA is used as a repair template. It is the latter which allows precise genome editing: the homologous section of DNA with the required sequence change may be delivered with the Cas9 nuclease and sgRNA, theoretically allowing changes as precise as a single base-pair.
See this image and copyright information in PMC

References

    1. Hsu PD, Lander ES, Zhang F. Development and Applications of CRISPR-Cas9 for Genome Engineering. Cell 2014;157:1262–78. 10.1016/j.cell.2014.05.010 - DOI - PMC - PubMed
    1. Yin H, Xue W, Chen S, et al. Genome editing with Cas9 in adult mice corrects a disease mutation and phenotype. Nat Biotech 2014;32:551–3. 10.1038/nbt.2884 - DOI - PMC - PubMed
    1. Liang P, Xu Y, Zhang X, et al. CRISPR/Cas9-mediated gene editing in human tripronuclear zygotes. Protein Cell 2015;6:363–72. 10.1007/s13238-015-0153-5 - DOI - PMC - PubMed
    1. Schwank G, Koo BK, Sasselli V, et al. Functional repair of CFTR by CRISPR/Cas9 in intestinal stem cell organoids of cystic fibrosis patients. Cell Stem Cell 2013;13:653–8. 10.1016/j.stem.2013.11.002 - DOI - PubMed
    1. Tabebordbar M, Zhu K, Cheng JK, et al. In vivo gene editing in dystrophic mouse muscle and muscle stem cells. Science 2016;351:407–11. 10.1126/science.aad5177 - DOI - PMC - PubMed

Substances