WCRB2014 POSTER PRESENTATIONS (1) (335 abstracts)
1University of Miyazaki, Miyazaki, Japan, 2RIKEN BRC, Tsukuba, Japan, 3National Institute of Biomedical Innovation, Tsukuba, Japan, 4Research Institute for Microbial Diseases, Osaka University, Suita, Japan
Introduction: The type II bacterial clustered regularly interspaced short palindromic repeat (CRISPR) and CRISPR-associated protein (Cas) have been proven to be an effective gene targeting system. Genome editing of non-rodent mammalian species is a promising strategy for generation of animal models for human diseases. Mashiko et al. reported a high efficacy of direct injection of a plasmid DNA, encoding humanized Cas9 and sgRNA (single-guide RNA) in mice. Here we show successful gene targeting in rabbit via the same strategy.
Materials and methods: To establish a CRISPR/Cas9 system in rabbit, we selected the TYROSINASE gene as a target using Dutch-belted rabbits. Plasmid pX330 was inserted with a candidate gRNA for the evaluation of endonuclease activity by single strand annealing (SSA) assay. Circular plasmid containing a selected gRNA was microinjected into the pronucleus of rabbit fertilized embryos. The embryos were cultured for 24 h and then transferred into the oviducts of pseudo-pregnant Japanese White rabbits.
Result and discussion: Four candidate gRNAs were evaluated by SSA assay and then circular prasmid pX330 containing TYROSINASE CR2 as a gRNA sequence was microinjected into 77 embryos. Of them, 67 (87%) were cleaved and transferred into recipients. Among 9 (13%) pups obtained at term, 2 (3%) had targeted alleles. One heterologous and one homologous mutant pups were obtained, although the latter was still born. This study demonstrated that the CRISPR/Cas9 system by direct injection of plasmid DNA into zygotes can also be potentially applicable to rabbits.