Incudible CRISPR/dCas9 based interference and activation screening system

In this study, we conducted a small-scale, tractable genetic screening tool to assess the contribution of essential genes from Plasmodium falciparum by using the conditional CRISPR/deadCas9-based interference and activation (i/a) systems. We screened both CRISPRi and CRISPRa sets, consisting of nine parasite lines after the targeted genes were repressed and activated by their respective gRNAs. By amplicon sequencing of gRNA loci, we identified the contribution of each targeted gene to parasite fitness upon drug (artemisinin and chloroquine) and stress (low glucose starvation and heat shock) treatment. We demonstrated that these screening systems are a robust and efficient tool to study essential genes.