KCS

Genome engineering that allows targeted mutagenesis in higher eukaryotic cells and organisms is broadly useful in biology, biotechnology, and medicine. Zinc finger nucleases (ZFNs) and transcription activator-like effector nucleases (TALENs) are powerful and versatile tools of genome editing, which are made by fusing custom-engineered DNA-binding zinc finger arrays and TALE arrays, respectively, to the FokI nuclease domain. We optimized the TALEN architecture to improve the efficiency and specificity and developed a high-throughput Golden-Gate cloning system to assemble TALEN plasmid in a genomic scale. We used these TALENs to establish single- and double-gene knockout cells in which NF-κB signaling pathways were disrupted. Compared to siRNA-treated cells, these cell lines showed unambiguous suppression of signal transduction. We also used both ZFNs and TALENs to induce site-specific mutations in mice, zebrafish, and other animals.
In addition, we developed a novel genome editing technology based on RNA-guided endonucleases (RGENs). Cas9 is a sequence-specific endonuclease in type II CRISPR/Cas systems, which confer prokaryotes with adaptive immunity against invading phages and plasmids. Cas9 recognizes and cleaves target DNA sequences complementary to small synthetic guide RNAs embedded in this protein, generating site-specific DNA double-strand breaks in vitro and in human cells, whose spontaneous repair induces targeted genome modifications at high frequencies. Unlike ZFNs and TALENs, RGENs are customized without any cloning step, making them a broadly useful, scalable and expeditious platform for genome editing in cells and organisms.