The Guangzhou Institute of Biology of the Chinese Academy of Sciences has achieved a number of single base editing on pigs

July 3, reporters from China
Guangzhou Institute of Biomedicine and Health was informed that the institute researcher Lai Liangxuan team used a single base editor for the first time in pigs to achieve a number of single base editing. It is reported that the application of this achievement will accelerate the cultivation of biomedically related large animal pig models and agricultural precision breeding. The study was published June 28 in Nature-Newsletter.
Lai Liangxuan said that the study for the first time from the cell, embryo and animal three levels to explore the feasibility of single-base editor for pig multi-gene simultaneous mutation, and through soda cell nuclear transfer and embryo injection two ways to obtain two unit-point single-base mutant pig model (Du's muscular dystrophy and premature aging pig model) and a three-point single-base mutant pig model (severe immunodeficiency pig model).
single base editor is a new gene editing system that has only recently emerged and is considered a version of gene editing technology 3.0. Earlier gene-editing tools such as Cas9 were associated with DNA fractures, which caused instability in the genome and pose a safety risk to the edited organism.
single base editor, it was soon widely used in gene editing in animals, plants, and human cells. However, previous studies have focused on base mutations at unit points. Human genetic diseases and changes in animal genetic features often involve single-base mutations at multiple points, so single-base editing of multiple bits of the genome is more likely to produce large animal models that can simulate human genetic diseases and new breeds of livestock and poultry with good genetic conditions.
researchers used be3 and A3A-BE3 single-base editing tools to edit the genome at the cellular and embryonic levels, with each gene designing a gRNA that mutates into a termination cryptocyte or mutate induces a new mRNA shearing point. On fetal embryos, the three genes are edited simultaneously for up to 50%. At the cellular level, the three genes can be edited up to 25% at the same time. Endogeneic retrovirus is present in many animals, and endogeneic viruses with the same gene family are often distributed in multiple copies at different site points of chromosomes. The presence of pig endogenetic virus brings safety hazards to pigs as donors of heterogeneic transplanted organs.
the study also performed a single base mutation on the pol gene associated with the replication of endovirus in pigs, creating an early termination cryptopron, thus achieving multiple point indescing of a single gene. Through second-generation sequencing analysis, it can be seen that in somogeneic cells, the knock-out rate of multiple copies reached more than 80%, while at the embryonic level, 71% of viral copies were knocked out. Therefore, this study proves that the single base editing system can achieve high-efficiency base mutation of multiple genes or single gene multiple points in both cell and embryonic water.
, it is understood that the study further through embryo injection and sodocyte nuclear cloning, respectively, to cultivate single-gene mutant pigs and multi-gene mutant pigs. The resulting pig models of Duchenne muscular dystrophy (DMD) with single-gene mutations, as well as the hutchinson-Gilford Progeria Syndrome (HGPS) pig models, are excellent simulations of the patient's esoteric model. The thymus and spleen development of the three genes (RAG1, RAG2, IL2RG) associated with immune cell development is obviously defective, T cells, B cells and NK cells are missing, immune cells cannot be rearmed with V(D) J genome, and have a typical severe immunodeficiency esoteric esoteric. Because pigs have very similar immune systems to humans, this model of severe immunodeficiency pigs will become an important genetic modification tool in the field of biomedical research.
co-author of the paper are Lai Liangxuan Researcher and Wang Co-researcher. Xie
, Ge Weikai, Li Nan and Liu Qishuai, Ph.D. students from Guangzhou Institute of Biology, are co-authors.
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