A beginner's guide to gene editing.

What is the topic of this review? This review summarizes the development of gene editing from early proof-of-concept studies in the 1980s to contemporary programmable and RNA-guided nucleases, which enable rapid and precise alteration of DNA sequences of almost any living cell. What advances does it highlight? With an average of one clustered regularly interspaced short palindromic repeat (CRISPR) Cas9 paper published every 4 h in 2017, this review cannot highlight all new developments, but a number of key improvements, including increases in efficiency, a range of new options to reduce off-target effects and plans for CRISPR to enter clinical trials in 2018, are discussed. Genome editing enables precise changes to be made in the genome of living cells. The technique was originally developed in the 1980s but largely limited to use in mice. The discovery that a targeted double-stranded break at a unique site in the genome, close to the site to be changed, could substantially increase the efficiency of editing raised the possibility of using the technique in a broader range of animal models and, potentially, human cells. But the challenge was to identify reagents that could create targeted breaks at a unique genomic location with minimal off-target effects. In 2005, the demonstration that programmable zinc finger nucleases (ZFNs) could perform this task led to a number of proof-of-concept studies, but a limitation was the ease with which effective ZFNs could be produced. In 2009, the development of TAL effector nucleases (TALENs) increased the specificity of gene editing and the ease of design and production. However, it was not until 2013 and the development of the clustered regularly interspaced short palindromic repeat (CRISPR) Cas9/guide RNA that gene editing became a research tool that any laboratory could use.

Harrison PT ，Hart S 《-》

Genome editing comes of age.

Kim JS 《-》

CRISPR/Cas9: an advanced tool for editing plant genomes.

Samanta MK ，Dey A ，Gayen S 《-》

Advances in therapeutic CRISPR/Cas9 genome editing.

Targeted nucleases are widely used as tools for genome editing. Two years ago the clustered regularly interspaced short palindromic repeat (CRISPR)-associated Cas9 nuclease was used for the first time, and since then has largely revolutionized the field. The tremendous success of the CRISPR/Cas9 genome editing tool is powered by the ease design principle of the guide RNA that targets Cas9 to the desired DNA locus, and by the high specificity and efficiency of CRISPR/Cas9-generated DNA breaks. Several studies recently used CRISPR/Cas9 to successfully modulate disease-causing alleles in vivo in animal models and ex vivo in somatic and induced pluripotent stem cells, raising hope for therapeutic genome editing in the clinics. In this review, we will summarize and discuss such preclinical CRISPR/Cas9 gene therapy reports.

Savić N ，Schwank G 《-》

Applications of Alternative Nucleases in the Age of CRISPR/Cas9.

Guha TK ，Edgell DR 《INTERNATIONAL JOURNAL OF MOLECULAR SCIENCES》