杜邦先锋公司开发出了首款DNA-free基因编辑玉米

将CRISPR-Cas9蛋白和gRNA在体外组装成核糖核蛋白复合体，再利用基因枪转化，就可以得到全程无DNA作为载体的基因编辑作物产品，该产品的优势是编辑效率高、脱靶率低、非预期变异少、背景纯合易。如今，种业巨头杜邦先锋公司已成功利用该技术得到了玉米基因编辑植株，性状表现为磺酰脲类除草剂抗性、雄性不育和叶舌缺失。

继杂交糯玉米之后，杜邦先锋公司在玉米基因编辑技术上又有了新的斩获，这是否意味着杜邦先锋在作物编辑育种领域已经领先了半个身位？

Nature Communications 7: 13274. 16 November 2016

Genome editing in maize directed by CRISPR–Cas9 ribonucleoprotein complexes

Author

Sergei Svitashev, Christine Schwartz, Brian Lenderts, Joshua K. Young& A. Mark Cigan

Trait Enabling Technologies, DuPont Pioneer, USA

Abstract

Targeted DNA double-strand breaks have been shown to significantly increase the frequency and precision of genome editing. In the past two decades, several double-strand break technologies have been developed. CRISPR–Cas9 has quickly become the technology of choice for genome editing due to its simplicity, efficiency and versatility. Currently, genome editing in plants primarily relies on delivering double-strand break reagents in the form of DNA vectors. Here we report biolistic delivery of pre-assembled Cas9–gRNA ribonucleoproteins into maize embryo cells and regeneration of plants with both mutated and edited alleles. Using this method of delivery, we also demonstrate DNA- and selectable marker-free gene mutagenesis in maize and recovery of plants with mutated alleles at high frequencies. These results open new opportunities to accelerate breeding practices in a wide variety of crop species.