Generating PARP Knockout D. melanogaster with CRISPR/Cas9 System.

Long-branched negatively charged poly(ADP-ribose) (pADPr) is a posttranslation modification of nuclear proteins that play a key role in many chromatin remodeling events. While several enzymes of PARP family could synthesize it across all multicellular organisms, Drosophila melanogaster is very suitable model to study pADPr-regulated processes because only one PARP gene is present. Despite the fact that PARP is an intensively studied protein with multiple important functions, no total knockout PARP flies were obtained in mobile element mutagenesis-based projects, mainly because PARP gene localizes in heterochromatic region. Here, we describe all steps of generating PARP mutated D. melanogaster with CRISPR/Cas9 system from the gRNA design, plasmid cloning to fly crosses and mutation detection. Provided gRNAs sequences target the region with high efficiency and results in more than 90% mutant stocks. This method could also be modified to generate PARP mutations in other gene locus, knockins with donor sequences for homology recombination or to be adjusted for other pADPr turnover-regulating enzymes.