Elucidation of potential sequences that can be unintentionally edited as a result of genome editing

2021 Fiscal Year Final Research Report

• Project/Area Number: 20K20255
• Research Category: Grant-in-Aid for Early-Career Scientists
• Allocation Type: Multi-year Fund
• Review Section: Basic Section 90140:Medical technology assessment-related
• Research Institution: National Institute of Health Sciences
• Principal Investigator: Yamashita Takuma 国立医薬品食品衛生研究所, 遺伝子医薬部, 研究員 (10866528)
• Project Period (FY): 2020-04-01 – 2022-03-31
• Keywords: ゲノム編集 / オフターゲット変異 / CRISPR-Cas

Outline of Final Research Achievements

Recently, genome editing technology using the CRISPR-Cas9 is expected to be used for therapeutic applications. However, off-target mutations caused by cleavage of sequences similar to the target sequence are a safety concern. In this study, we evaluated the sequences that can be cleaved by Cas9. The results showed that Cas9 can cleave sequences that contain mismatches of up to a few bases with the target sequence and that the PAM sequence recognized by Cas9 is not a canonical sequence.

Free Research Field

レギュラトリーサイエンス

Academic Significance and Societal Importance of the Research Achievements

本研究の結果から、ゲノム編集に伴うオフターゲット変異候補部位の予測評価の際には、ガイドRNAとの相補性を指標に、非典型的なPAM配列も含めて評価する必要があることが示された。現在利用されているオフターゲット変異予測プログラムではこのような配列が考慮されていない場合があり、起こりうるオフターゲット変異を見逃してしまう可能性に注意が必要であると考えられる。