CRISPR/Cpf1 mediated genome editing enhances Bombyx mori resistance to BmNPV

CRISPR/Cas12a (Cpf1) is a single RNA-guided endonuclease that provides new opportunities for targeted genome engineering through the CRISPR/Cas9 system. Only AsCpf1 have been developed for insect genome editing, and the novel Cas12a orthologs nucleases and editing efficiency require more study in insect. We compared three Cas12a orthologs nucleases, AsCpf1, FnCpf1, and LbCpf1, for their editing efficiencies and antiviral abilities in vitro. The three Cpf1 efficiently edited the BmNPV genome and inhibited BmNPV replication in BmN-SWU1 cells. The antiviral ability of the FnCpf1 system was more efficient than the SpCas9 system after infection by BmNPV. We created FnCpf1×gIE1 and SpCas9×sgIE1 transgenic hybrid lines and evaluated the gene editing efficiency of different systems at the same target site. We improved the antiviral ability using the FnCpf1 system in transgenic silkworm. This study demonstrated use of the CRISPR/Cpf1 system to achieve high editing efficiencies in the silkworm, and illustrates the use of this technology for increasing disease resistance.Author SummaryGenome editing is a powerful tool that has been widely used in gene function, gene therapy, pest control, and disease-resistant engineering in most parts of pathogens research. Since the establishment of CRISPR/Cas9, powerful strategies for antiviral therapy of transgenic silkworm have emerged. Nevertheless, there is still room to expand the scope of genome editing tool for further application to improve antiviral research. Here, we demonstrate that three Cpf1 endonuclease can be used efficiency editing BmNPV genome in vitro and in vivo for the first time. More importantly, this Cpf1 system could improve the resistance of transgenic silkworms to BmNPV compare with Cas9 system, and no significant cocoons difference was observed between transgenic lines infected with BmNPV and control. These broaden the range of application of CRISPR for novel genome editing methods in silkworm and also enable sheds light on antiviral therapy.