CRISPR class 2蛋白的基因组编辑应用相信之前几期的CRISPR介绍，以及上周讲了CRISPR的原理的讲解，大家对CRISPR有不少认识了吧。那么本期，介绍下CRISPR在哪些物种中进行基因组编辑工作了呢？

基于Cas9的基因编辑技术目前已经得到了广泛的应用，例如对特定基因功能的研究，疾病模型建立，以及遗传和感染性疾病治疗的研究等等1-3。

成功建立CRISPR-Cas9基因组编辑体系的宿主也在不断增加，从刚开始的细菌4，人细胞的应用5, 6，后来又拓展到酵母7、植物8, 9、线虫10、斑马鱼11，甚至是人胚胎12。

另外，如果通过引入多个sgRNA，Cas9可以同时切割多个位点。这可以应用于大规模的染色体重排13。例如，设计一对在同一染色体上靶标距离相近的sgRNA，这会引起靶标序列的删除，或者DNA片段的倒位，如果是同时靶向到不同的染色体，可能就会引起染色体的易位。这些Cas9介导的染色体重排，对构建人的疾病模型非常有用（比如癌症和一些遗传学疾病）14, 15。

在Cas12a（旧称Cpf1）蛋白发现后并证明了人细胞可基因组编辑后，越来越多的文章证明了该蛋白在不同物种中进行基因组编辑的有效性，包括细菌，植物，小鼠等16-26，并且还包括不适合利用Cas9进行基因组编辑的物种20。另外，有文章测试Cas12a在人细胞内的脱靶率明显低于Cas9，而切割效率相当27。

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