Developing CRISPR/Cas9 Technologies for Research and Medicine

CRISPR/Cas, comprised of Clustered regularly interspaced short palindromic repeats (CRISPR) and associated proteins (Cas), provides adaptive immunity against foreign DNA in bacteria and archaea. Type II CRISPR/Cas9 has attracted considerable interest as a tool to probe and manipulate biological systems. It has been engineered to introduce genome editing in a simple, flexible, and efficient manner. Various approaches have been explored to reduce the off-target effects, which limit its applications in certain circumstances. Moreover, a catalytically inactive Cas9 was used to guide various effectors and a labeling agent to specific DNA targets through protein fusion, thus enabling genetic/epigenetic regulation and visualizing specific genomic loci in living cells. Further, CRISPR/Cas9 could have a significant impact on medicine by facilitating the generation of cell lines and animal models for therapeutic screening and evaluation, and by providing a new promising avenue for gene therapy.