美国杜克大学Charles A. Gersbach团队开发出基于CRISPR系统进行体内表观基因组编辑的转基因小鼠。相关论文于2021年8月2日在线发表于国际学术期刊《自然—方法学》。

研究人员描述了两个用于表观基因组编辑的条件性转基因小鼠品系的产生和特征，Rosa26:LSL-dCas9-p300用于基因激活，Rosa26:LSL-dCas9-KRAB用于基因抑制。通过将向导RNA定位于转录起始位点或远端增强子元件，研究人员证明了目标基因的调控和表观遗传状态的相应变化以及在体内和体外T细胞和成纤维细胞中的下游表型。这些小鼠品系是方便和有价值的工具，可用于便捷、时间操控和组织限制的表观基因组编辑和体内基因表达的操纵。

据悉，CRISPR-Cas9技术极大地增加了针对生物系统基因组中DNA序列的便利性。染色质修饰域与dCas9的融合使培养细胞和动物模型的表观基因组定向编辑成为可能。然而，将大型dCas9融合蛋白运送到目标细胞和组织是广泛采用这些工具进行体内研究的一个障碍。

附：英文原文

Title: Transgenic mice for in vivo epigenome editing with CRISPR-based systems

Author: Gemberling, Matthew P., Siklenka, Keith, Rodriguez, Erica, Tonn-Eisinger, Katherine R., Barrera, Alejandro, Liu, Fang, Kantor, Ariel, Li, Liqing, Cigliola, Valentina, Hazlett, Mariah F., Williams, Courtney A., Bartelt, Luke C., Madigan, Victoria J., Bodle, Josephine C., Daniels, Heather, Rouse, Douglas C., Hilton, Isaac B., Asokan, Aravind, Ciofani, Maria, Poss, Kenneth D., Reddy, Timothy E., West, Anne E., Gersbach, Charles A.

Issue&Volume: 2021-08-02

Abstract: CRISPR-Cas9 technologies have dramatically increased the ease of targeting DNA sequences in the genomes of living systems. The fusion of chromatin-modifying domains to nuclease-deactivated Cas9 (dCas9) has enabled targeted epigenome editing in both cultured cells and animal models. However, delivering large dCas9 fusion proteins to target cells and tissues is an obstacle to the widespread adoption of these tools for in vivo studies. Here, we describe the generation and characterization of two conditional transgenic mouse lines for epigenome editing, Rosa26:LSL-dCas9-p300 for gene activation and Rosa26:LSL-dCas9-KRAB for gene repression. By targeting the guide RNAs to transcriptional start sites or distal enhancer elements, we demonstrate regulation of target genes and corresponding changes to epigenetic states and downstream phenotypes in the brain and liver in vivo, and in Tcells and fibroblasts ex vivo. These mouse lines are convenient and valuable tools for facile, temporally controlled, and tissue-restricted epigenome editing and manipulation of gene expression in vivo.

DOI: 10.1038/s41592-021-01207-2

Source: https://www.nature.com/articles/s41592-021-01207-2