The new study enables simultaneous activation of multi-genes in the brain of genetically modified mice.

On January 15th, Nature Neuroscience published a research paper entitled "Using CRISPR/dCas9 genetically modified mice to activate multiple genes simultaneously in the brain", which was completed by the Institute of Neuroscience of the Shanghai Institute of Life Sciences of the Chinese Academy of Sciences, the Center for Excellence in Brain Science and Intelligent Technology, and the Yang Hui Research Group of the National Key Laboratory of Neuroscience in collaboration with Huang Pengyu Laboratory of Shanghai University of Science and Technology.
the study established an efficient inviviable activation platform based on CRISPR/dCas9, and simultaneously activated multiple gene components, including genes and long-chain non-coding RNAs, in the mouse brain.
the establishment of the activation system in the body will provide an important technical means for the study of complex genetic networks and acquired phenotypes in the brain.
has long had a technique that can control gene expression at will is the dream of many biologists.
the emergence of the CRISPR/Cas9 system to meet this need, Cas9 is like a DNA scissors, led by sgRNA, specifically cutting the purpose sequence, and forming a DNA double-stranded fracture.
later study obtained Casdead9 (i.e. dCas9) by inactivating the activity of Cas9's nucleic acid endoenzyme, which only binds specifically to the destination site under the guidance of sgRNA, without producing cutting.
if the activation element is fused on dCas9, the gene of the intended expression can be specifically overexpressed.
this approach has a huge advantage over traditional overexpression, because it is not limited by the size of the gene, it can easily increase the expression of multiple genes at the same time, and this overexpression is more "natural".
although dCas9-mediated gene activation has been widely used in vitro research, the use of dCas9 to control gene expression in the body has not been achieved.
the study, the researchers first developed a more powerful activation system (SPH) than in the past, and demonstrated the efficiency of the SPH system in human and mouse cells.
on this basis, the researchers constructed SPH genetically modified mice regulated by Crererereenzyme, and demonstrated that the introduction of sgRNA and Creremodifiase into the primary cells of SPH mice activates genes and long-chain non-coding RNA.
to determine the effectiveness of the genetically modified mice in the invivies, the researchers injected plasmids expressing Cre and sgRNA through tailves, and found that SPH can effectively activate gene expression in the liver.
especially after activating Dkk1, the key gene in the Wnt pathway, the metabolic region of the liver is altered.
To further verify whether the activation platform can be used to study the function of the nervous system, the researchers injected AAV-sgRNA targeting three transcription factors, Ascl1, Neurog2, and Neurod1, to show that astrocytes can be converted directly into functional neurons.
finally, the researchers injected a Single-sgRNA array of 10 genes or eight genes plus two long-chain non-coding RNA in the brains of SPH genetically modified mice, enabling multiple genes to activate within neurons at the same time.
this study proves that SPH mice can be used to regulate complex genetic networks in the brain.
the work was mainly done by postdoctoral students Zhou Haibo, Ph.D. students Liu Junlai, Zhou Changyang, Gao Ni, Rao Zhiping, Li He, under the joint guidance of Yang Hui, a researcher in the Research Group of primate diseases of the Institute of Neurology, and Huang Pengyu of Shanghai University of Science and Technology.
work has been supported by the Chinese Academy of Sciences' strategic leading science and technology project, the national high-tech research and development project, the Chinese Youth Thousand People Program, the Chinese Academy of Sciences' major breakthrough project, the National Natural Science Foundation and the Ministry of Science and Technology.
the study summary pattern diagram.
the study first developed the SPH activation system and constructed SPH genetically modified mice regulated by Crererereenzyme, and the researchers demonstrated that the mice could be used to alter the metabolic partition of the liver, direct transpolarization of astrocytes to neurons, and activation at the same time as multiple genes were implemented in the brain.
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