Abstract: The study of gene function in insects is restricted by lacking of relevant tools. However, the emergence of CRISPR/Cas9 system provides great help for the research of gene editing and transcriptional regulation in insects. dCas9 with catalytically dead mutant RuvC and HNH domains of Cas9 has been widely used in the transcriptional regulation of genes in recent years. Meanwhile, CRISPR/dCpf1 and the newly discovered CRISPR/Cas13(a/b) systems provide more options for gene function research. In this article, the mechanism of dCas9, dCpf1 and Cas13(a/b) systems and the progress of their application in the transcriptional regulation in Drosophila were systematically overviewed, aiming to provide a reference for future related studies of insects.

Key words: CRISPR, guide RNA, dCas9, dCpf1, Cas13(a/b), transcriptional regulation