Prior to the discovery and the development of the ZFN, TALE and CRISPR/Cas methods, genome targeting and editing seemed to have more negative effects than positive due to the amount of time and effort it required and the …show more content…
The CRISPR system works by cleaving a point along foreign DNA and placing what are called “spacers” in order to stop or reduce the effect that pathogenic DNA has by developing an immunity in that pathogen because it has been introduced in small portions into the host’s sequence. The CRISPR/Cas system is capable of cleaving almost any DNA sequence as long as the design of the crRNA has the appropriate binding region for the system. It is uncertain if the CRISPR/Cas system exhibits the selectivity that is needed to make sure that single sites are being targeted in complex genomes. Unlike TALE proteins and the ZFN, the CRISPR/Cas9 system uses a guide RNA (gRNA) to target the desired gene with the matching RNA sequence. The CRISPR is the newest discovery of the gene editing technologies/systems and is, so far, the most reliable system and capable of multiplex genome engineering due to its ability to introduce multiple