Oligo-Mediated Targeted Gene Editing

Contribution in… / 2015

Gocal, Greg F. W.; Schöpke, Christian; Beetham, Peter R.

Oligonucleotide-mediated targeted gene editing encompasses technology described by many names. These include Oligo-Directed Mutagenesis (ODM) and the commercial Rapid Trait Development System (RTDS™) from Cibus. ODM is a non-transgenic (non-GMO) base pair-specific oligonucleotide-directed gene editing platform that has been advanced at Cibus over the past decade and has achieved novel and commercially valuable traits in crops. This technology harnesses the cell’s normal DNA repair system to correct and change specific targeted bases within the genome of a cell. The Gene Repair OligoNucleotide (GRON), a chemically synthesized oligonucleotide, is designed to create mismatched base pairs compared to the target sequence within the host organism’s genome. The GRON hybridizes at the target region and the mismatched base pairs work to direct the cell’s repair system at those sites to correct (replace, insert, or delete) the designated base(s). Once the correction process is complete the GRON is degraded and the now-modified or repaired gene retains its normal pattern of expression and stability within the genome. This technique has been successfully deployed in bacterial, fungal, mammalian, and plant systems. Our work in achieving herbicide tolerance traits in acetohydroxyacid synthase (AHAS) genes in oil seed rape (OSR) as well as work converting a blue fluorescent protein (BFP) transgene to green fluorescent protein (GFP) in an Arabidopsis model system will be discussed.