Current advances in CRISPR-Cas-mediated gene editing and regulation in cyanobacteria

Abstract Photosynthetic cyanobacteria are important microbial models in basic research such as photosynthesis, biological rhythm, and the geochemical cycle of elements. Meanwhile, they attract significant attention to serve as "autotrophic cell factories", enabling the production of dozens of chemicals. In this case, genetic toolboxes especially gene editing and regulation tools with high efficiency are the basis of the development of related studies. Among them, clustered regularly interspaced palindromic repeats (CRISPR)-Cas related technologies have realized rapid and efficient gene editing, gene silence and activation in multiple organisms like Escherichia coli , budding yeast, plant and mammalian cells. To promote their understandings and applications in cyanobacteria, in this review, advances in CRISPR-Cas-mediated gene editing and regulations were critically discussed. Firstly, the elucidation of native CRISPR-Cas in cyanobacteria were concluded, which provided new tool candidates for further optimization. Secondly, basic principles and applications of CRISPR-Cas related gene editing and regulation tools used in cyanobacteria were respectively discussed. In the future, further studies on development of native CRISPR-Cas tools, continuous editing and dynamic regulation would significantly promote the synthetic biology researches in cyanobacteria.