CRISPR/Cas9: a New Era of Gene Editing

Gene editing techniques use endonucleases to make desired changes within genomic DNA by insertion, deletion or substitution of DNA sequences. Four types of endonucleases are commonly used as gene editing tools: meganucleases, zinc finger nucleases, transcription activator-like effector nucleases, and CRISPR/Cas9 systems. Among these tools, the CRISPR/Cas9 system is a new gene editing technology remarked for simplicity, good targeting specificity and high cutting efficiency. This article reviews structural and functional characteristics of CRISPR/cas9 systems, as well as their current or potential applications in editing of animal and plant genes and treatment of human genetic diseases, viral diseases, and tumors. Current progress in research and applications of CRISPR/Cas9 systems is summarized and future perspectives are discussed.