CRISPR-Csy4-Mediated Editing of Rotavirus Double-Stranded RNA Genome.

CRISPR-nucleases have been widely applied for editing cellular and viral genomes, but nuclease-mediated genome editing of double-stranded RNA (dsRNA) viruses has not yet been reported. Here, by engineering CRISPR-Csy4 nuclease to localize to rotavirus viral factories, we achieve the nuclease-mediated genome editing of rotavirus, an important human and livestock pathogen with a multisegmented dsRNA genome. Rotavirus replication intermediates cleaved by Csy4 is edited through the formation of precise deletions in the targeted genome segments in a single replication cycle. Using CRISPR-Csy4-mediated editing of rotavirus genome, we label the products of rotavirus secondary transcription made by newly assembled viral particles during rotavirus replication, demonstrating that this step largely contributes to the overall production of viral proteins. We anticipate that the nuclease-mediated cleavage of dsRNA virus genomes will promote an advanced level of understanding of viral replication and host-pathogen interactions, also offering opportunities to develop therapeutics.