In this new method, the RNA aptamers engineered in crRNA scaffold recruit their cognate binding proteins fused with cytidine deaminase and adenosine deaminase to Cas9 nickase target sites, leading to multiplexed base-editing. When paired sgRNAs are used, SWISS can cause insertions or deletions in addition to base editing. When this method was tested in rice, the mutants generated exhibited efficiencies of cytosine conversion of 25.5%, adenine conversion of 16.4%, indels of 52.7%, and simultaneous triple mutations of 7.3%.
Based on the tests, the SWISS system is a powerful tool for multi-functional genome editing in plants.
For more findings, read the open-access article at Genome Biology.