操纵子典型结构（曲柄摇杆及曲柄滑块的组成部分）

图7：CBE系统的分类（Cheng et al. 2019）CBE 系统的活性窗口定义为 sgRNA 中编辑效率>40%的C位点。（a）前置型CBE（FSCBEs），其活性窗口主要位于sgRNA靶位点的前端（PAM位点看作最末端）。（b）后置型 CBE（BSCBEs），活性窗口主要位于 sgRNA 靶位点的后端。（c）广谱型 CBE（BRCBEs），活性窗口横跨 sgRNA 靶位点的前后端。

单碱基编辑技术有着相当广泛的应用（图8），它在动物模型的构建、疾病治疗、作物育种以及点突变筛选等等多个方面都极具潜力 [13]。开发安全性高、适用范围广的单碱基编辑工具将有助于其潜力的兑现，从而更好的服务于生物医学研究。新的 CBE 工具在安全性和适用范围上均取得了相当大的进步，为单碱基编辑技术的进步做出了贡献。

操纵子典型结构,曲柄摇杆及曲柄滑块的组成部分(9)

图8 单碱基编辑技术的应用前景（改自K.A.Molla et al. 2019）

作者简介

程田林博士，助理研究员，中国科学院脑科学与智能技术卓越创新中心，中国科学院神经科学研究所

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