CRISPR (clustered regularly interspaced short palindromic repeat) is a segment of nucleic acid containing short, repetitive base sequences derived from DNA fragments of bacteriophages that had previously infected prokaryotic cells. These sequences, found in prokaryotic genomes, play an important role in prokaryotic defense. The prokaryotic immune system consisting of CRISPR and Cas (CRISPR-associated) proteins now form the basis of genome editing technology. CRISPR-mediated genome editing is a rapidly expanding field. In addition to its widespread use in basic biology research such as gene knockdown or knock-in, gene repression or activation, genomic DNA tagging, and gene screening, the CRISPR-Cas system is also a powerful tool for the development of biological products and therapeutics.
CRISPR-Based Technology
The core concept of synthetic biology is to construct artificial decision-making circuits by building and integrating standardized components and modules. The early stage of synthetic biology mainly focused on microbial engineering, while the recent work has extended to engineering mammalian systems. As a result, tools that can more efficiently and precisely control gene expression are needed. However, the lack of sequence-specific, programmable, predictable, effective, and safe gene editing tools is an ultimate challenge in the construction of genetic circuits. Complex genetic circuits based on CRISPR allow for more precise regulation of gene expression in terms of levels and timing than traditional methods. Gene expression control based on the prokaryotic adaptive immunity system CRISPR has emerged as a powerful platform for the construction of synthetic genetic circuits.