The Application of CRISPR-Cas9 Genome Editing in Caenorhabditis elegans

Genome editing using the Cas9 endonuclease of Streptococcus pyogenes has demonstrated unparalleled efficacy and facility for modifying genomes in a wide variety of organisms. Caenorhabditis elegans is one of the most convenient multicellular organisms for genetic analysis, and the application of this novel genome editing technique to this organism promises to revolutionize analysis of gene function in the future. CRISPR-Cas9 has been successfully used to generate imprecise insertions and deletions via non-homologous end-joining mechanisms and to create precise mutations by homology-directed repair from donor templates. Key variables are the methods used to deliver the Cas9 endonuclease and the efficiency of the single guide RNAs. CRISPR-Cas9-mediated editing appears to be highly specific in C. elegans, with no reported off-target effects. In this review, I briefly summarize recent progress in CRISPR-Cas9-based genome editing in C. elegans, highlighting technical improvements in mutagenesis and mutation detection, and discuss potential future applications of this technique.