Genome Editing in Caenorhabditis briggsae using the CRISPR/Cas9 System

Author Summary The CRISPR/Cas9 system has recently emerged as a powerful tool to engineer the genome of an organism. The system is adopted from bacteria where it confers immunity against invading foreign DNA. This work reports the first successful use of the CRISPR/Cas9 system in C. briggsae , a cousin of the well-known nematode C. elegans . We used two plasmids, one expressing Cas9 endonuclease and the other an engineered CRISPR RNA corresponding to the DNA sequence to be cleaved. Our approach allows for the generation of loss-of-function mutations in C. briggsae genes thereby facilitating a comparative study of gene function between nematodes. Abstract The CRISPR/Cas9 system is an efficient technique for generating targeted alterations in an organism’s genome. Here we describe a methodology for using the CRISPR/Cas9 system to generate mutations via non-homologous end joining in the nematode Caenorhabditis briggsae, a sister species of C. elegans . Evidence for somatic mutations and off-target mutations are also reported. The use of the CRISPR/Cas9 system in C. briggsae will greatly facilitate comparative studies to C. elegans.