shengjian, y.; YanChen, L.; Chunhua, K.; YiChen, S.; Ma, Y.

Efforts have been directed towards genome editing in cyanobacteria, yet achieving genome reduction in cyanophages remains a challenging task. In this study, we utilized the CRISPR-Cas12a system to successfully delete multiple genes within A-1(L) and A-4(L) cyanophages. Through careful manipulation, we generated a deletion mutant cyanophage with a 2,778 bp reduction in genome size, representing a 6.6% decrease compared to the wild type (WT). In summary, our research has introduced a robust method for gene editing in cyanophages, facilitating the identification of nonessential genes essential for cyanophage propagation. This advancement holds promise in addressing the widespread issue of water blooms and the associated environmental hazards.