A new way to quickly analyze the function of lethal genes in various tissue organs.

On April 21st, the international journal Cell Research published the latest research results of Li Jinsong Research Group and Institute of Neuroscience Yu Xiang Research Group of the Institute of Biochemistry and Cell Biology, Shanghai Institute of Life Sciences, Chinese Academy of Sciences, in the form of Article: CRISPR-Cas9-mediated genome editing in one blastomere of two-cell embryos reveals a novel Tet3 function Using CRISPR/Cas9 technology and cell lineage tracer techniques, the study genetically knocked out a single cleavage ball in a mouse's two-cell embryo, obtained a healthy chime mouse with the Tet3 gene knockout, and explored the synaptic transmission of the cerebral cortical layer and hippocellular neurons after the Tet3 gene knockout.
method is a new method for quickly analyzing the function of dead genes in various tissue organs.
DNA double oxygenase Tet3 is an important member of the Tet protein family, and previous studies have found that parts of Tet3 systemic knockout mice can develop until birth, but die within 24 hours of birth.
, to study the function of Tet3 in adult mice, it is necessary to use the Cre/loxP system to specifically knock out in different tissues.
This raises a number of questions: whether the tissue to be studied has specific Cre mouse resources;
this, Li Jinsong's team proposed a rapid analysis of the potential function of lethal genes based on chimlines.
First, they injected Cas9 mRNA in a cell period (fertilized egg period) in an mT/mG mouse embryo, and then randomly injected Cre mRNA and Tate3 sgRNAs in one of the two cells during the two cells.
The implantation of these injected embryos into a fake pregnant mouse gives you access to Tat3-knocked chimeric mice, which can live normally and have red/green cells present in various tissue organs, where red cells are wild and green cells are Tat3-knocked.
To simplify genotype identification and ensure knockout success rates, the researchers further injected multiple sgNRAs (3-4) into a single cleavage ball, a strategy that allowed mice to easily identify large fragments of knockout through PCR strips, while removing an entire exon to ensure the success rate of knockout.
analyzed the brains of these chiliosome mice and found that Tat3 knock-out did not affect the development and differentiation of the main cell types in the cerebral cortical layer.
researchers further performed pairs of electrophysiological records on adjacent wild type and Tat3 knockout cells and found that after Tat3 knock-out, both excitability and inhibitory synaptic delivery of neurons in the cerebral cortical layer and hippocupal cone in mice were significantly altered, as shown by the upward adjustment of excitable synaptic delivery and the reduction of inhibitory synaptic delivery.
suggest that Tat3 plays an important role in the development of neural circuits in different brain regions of the brain.
The advantages of this technique lie mainly in the fact that, for lethal genes, chime mice can be obtained in one step to explore the role of the gene in different tissue organs;
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