Introduction to Genome Editing
There are various options to modulate gene expression, be it on the DNA, RNA, or protein level. Many of these options only result in a transient modulation that might be sufficient or even advantageous for some approaches. A stable, heritable DNA modification was accomplished either by random integration of plasmids, transposons, or viruses or via homologous recombination. The latter method results in site-specific integration but is a very time-consuming and inefficient process. With the introduction of advanced genome editing tools, site-specific stable modifications can now be performed easily.
Zinc Finger Nucleases (ZFN) and Transcriptional Activator-like Effector Nucleases (TALEN) technologies were established over the last decade as useful tools for site-specific genomic modifications, but with the recent discovery of the CRISPR (clustered regularly interspaced short palindromic repeats) technology another potent alternative has emerged.