Cytosine base editors induce off-target mutations and adverse phenotypic effects in transgenic mice

作者：Yan, Nana; Feng, Hu; Sun, Yongsen; Xin, Ying; Zhang, Haihang; Lu, Hongjiang; Zheng, Jitan; He, Chenfei; Zuo, Zhenrui; Yuan, Tanglong; Li, Nana; Xie, Long; Wei, Wu^*; Sun, Yidi^*; Zuo, Erwei^*

来源：Nature Communications, 2023, 14(1): 1784.

DOI：10.1038/s41467-023-37508-7

• GENOMIC DNA
• R PACKAGE
• CRISPR
• AAV

Base editors have been reported to induce off-target mutations in cultured cells, mouse embryos and rice, but their long-term effects in vivo remain unknown. Here, we develop a Systematic evaluation Approach For gene Editing tools by Transgenic mIce (SAFETI), and evaluate the off-target effects of BE3, high fidelity version of CBE (YE1-BE3-FNLS) and ABE (ABE7.10(F148A)) in similar to 400 transgenic mice over 15 months. Whole-genome sequence analysis reveals BE3 expression generated de novo mutations in the offspring of transgenic mice. RNA-seq analysis reveals both BE3 and YE1-BE3-FNLS induce transcriptome-wide SNVs, and the numbers of RNA SNVs are positively correlated with CBE expression levels across various tissues. By contrast, ABE7.10(F148A) shows no detectable off-target DNA or RNA SNVs. Notably, we observe abnormal phenotypes including obesity and developmental delay in mice with permanent genomic BE3 overexpression during long-time monitoring, elucidating a potentially overlooked aspect of side effects of BE3 in vivo.

• 单位
  广西大学; 华中农业大学; 中国科学院研究生院