动物实验,染色体敲除 z-bo 2020-09-04 417

　　A research paper jointly completed by Yang Hui’s research group from the Institute of Neuroscience, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Center for Excellence in Brain Science and Intelligent Technology, and Hu Jiazhi Laboratory of Peking University, uses CRISPR/Cas9-mediated gene editing technology to knock out target chromosomes "" as the title, published in "Genome Biology". This research introduces a new application of CRISPR/Cas9 technology, that is, in cells, embryos or in vivo tissues, multiple DNA shears are performed on target chromosomes to selectively eliminate single chromosomes. CRISPR/Cas9-mediated elimination of target chromosomes provides new strategies and methods for the establishment of animal models and the treatment of aneuploidy diseases.

　　The CRISPR/Cas9 system of

　　type II bacteria consists of Cas9 nuclease and single-stranded guide RNA (sgRNA). It has been transformed into an efficient gene editing tool that can significantly improve the ability to edit the genome. sgRNA guides Cas9 to a specific genomic region, shearing to form a double-stranded DNA gap, which can be repaired by two methods-non-homologous chromosome end joining repair or homologous recombination repair. CRISPR/Cas9 gene editing technology has been applied to produce cells or animals with precise gene mutation, recombination and knockout of chromosome fragments. The researchers asked whether the CRISPR/Cas9 gene editing technology can be used to eliminate entire chromosomes, thereby providing a new way for the establishment of animal models of chromosome deletion and the treatment of aneuploidy diseases.

　　To verify this idea, the researchers first demonstrated that the application of CRISPR/Cas9-mediated multi-site DNA cleavage targeting the Y chromosome can effectively eliminate Y staining of mouse embryonic stem cells. This multi-site splicing can be achieved by targeting a single sgRNA to bind to multiple specific chromosomal sites, or by combining 14 sgRNAs to their respective specific sites. In addition, they also found that mouse X chromosomes, human chromosomes 7 and 14 can be eliminated by this method. More importantly, chromosome 21 in iPS cells from Down syndrome patients can also be specifically eliminated by this method. Therefore, this study confirmed for the first time that sex chromosomes and autosomes can be specifically eliminated by gene editing.

　　The research work has been supported by the National Science and Technology Major Project, the Chinese Academy of Sciences Strategic Leading Science and Technology Project, the National High-Tech R&D Project (863 Project), the National Natural Science Foundation, and the Chinese Academy of Sciences Major Breakthrough.