Clustered regularly interspaced short palindromic repeats CRISPR/Cas9 technology evolved from a type II bacterial immune system develop in 2013 This system employs RNA-guided nuclease, CRISPR associated (Cas9) to induce double-strand breaks.The Cas9-mediated breaks are repaired by cellular DNA repair dea eyewear mechanisms and mediate gene/genome modifications.The system has the ability to detect specific sequences of letters within the genetic code and to cut DNA at a specific point.
Simultaneously with other sequence-specific nucleases, CRISPR/ Cas9 have already breach the boundaries and made genetic engineering much more versatile, efficient and easy also it has been reported to have increased rice grain yield up to 25-30 %, and increased tomato fruits size, branching architecture, and overall plant shape.CRISPR/ Cas also mediated virus resistance in many agricultural crops.In this article, we reviewed the history of the CRISPR/Cas9 system invention and its genome-editing mechanism.
We also described the most recent innovation of the CRISPR/Cas9 technology, particularly the broad applications of modified Cas9 variants, and discuss the potential of this system for targeted genome editing and modification for crop improvement.Abbreviations: CRISPR, clustered regularly interspaced short palindromic repeats; Cas, CRISPR associated; crRNA, CRISPR RNA; tracrRNA, trans-activating crRNA; PAM, protospacer adjacent motif; sgRNA, single guide truvisionhealthftp.com RNA; gRNA, guide RNA; ssODN, single-stranded DNA oligonucleotide; DSB, double-strand break; NHEJ, non-homologous end joining; HDR, homology directed repair, CRISPRi ,CRISPR interference.