Genome Tagging Project Center, Center for Excellence in Molecular Cell Science, Shanghai Institute of Biochemistry and Cell Biology, Chinese Academy of Sciences, Shanghai 200031, China.
Yi Chuan. 2021 Jul 20;43(7):704-714. doi: 10.16288/j.yczz.21-163.
Mice are the most widely used model organism for the study of gene functions and disease mechanisms through the generation of gene-modified mice. Since the 1980s, different genetic manipulation technologies have been developed to reveal gene functions in vivo, including homologous recombination strategies mediated by embryonic stem cells, transgenic strategies mediated by gametes, and the latest genetic modification strategies based on CRISPR/Cas9 technology. Semi-cloning technology mediated by "artificial spermatids" (androgenetic haploid embryonic stem cells, also termed sperm-like stem cells) is developed by Chinese scientists in 2012. In combination with CRISPR/Cas9, semi-cloning technology enables one-step generation of gene-modified mice through injection of "artificial spermatids" with specific gene modifications into oocytes. It has the characteristics of short construction cycle, high efficiency, low cost, and high application compatibility. In 2017, the Center for Excellence in Molecular Cell Science (CEMCS) of CAS has launched the genome tagging project (GTP) based on "artificial spermatid"-mediated semi-cloning technology. The ambitious goal of GTP is to tag every protein in mice and construct a unique mouse library that maintains the genome-wide protein-tagging mouse models. Subsequently, the GTP center was established at CEMCS to pursue the project. GTP center developed strategies to generate protein-tagging cells and mice. Briefly, a tag sequence is precisely inserted in a specific protein- coding gene endogenously in cultured "artificial spermatids"in vitro to build a cell library, in which, each cell line carrying a specific protein tag. The tagged cells could be further used as a sperm replacement to produce tagged mice in one step upon injection into oocytes. The tagged mouse library enables global analysis of protein expression, localization, and complexes using standard tag-based assays in vivo. By April 2021, the GTP center has generated 1532 tagged cell lines, 277 of which have been successfully used to produce tagged mice through oocyte injection. A total of 242 tagged mouse strains have been distributed to 66 research teams in 32 research institutions of 15 districts in 3 countries. The database of tagging product resources has been established and released regularly on the GTP website for scientists to inquire and order. Later, more information about GTP products, such as mouse breeding, protein tissue expression map, published literature, etc., will also be successively published on the GTP website. The GTP center will provide a standardized platform for protein function research, which may dramatically promote the development of life science and clinical transformation.
小鼠是研究基因功能和疾病机制的最广泛使用的模式生物，通过生成基因修饰小鼠来实现。自 20 世纪 80 年代以来，已经开发出不同的遗传操作技术来在体内揭示基因功能，包括由胚胎干细胞介导的同源重组策略、由配子介导的转基因策略，以及基于 CRISPR/Cas9 技术的最新遗传修饰策略。“人工精子”（雄原核胚胎干细胞，也称为精子样干细胞）介导的半克隆技术是中国科学家于 2012 年开发的。与 CRISPR/Cas9 结合使用，半克隆技术可通过将具有特定基因修饰的“人工精子”注射到卵母细胞中，一步生成基因修饰小鼠。它具有构建周期短、效率高、成本低、应用兼容性强的特点。2017 年，中国科学院分子细胞科学卓越创新中心（CEMCS）启动了基于“人工精子”介导的半克隆技术的基因组标记项目（GTP）。GTP 的雄心勃勃的目标是标记小鼠中的每一种蛋白质，并构建一个独特的保持全基因组蛋白标记小鼠模型的文库。随后，CEMCS 成立了 GTP 中心来推进该项目。GTP 中心开发了生成蛋白标记细胞和小鼠的策略。简而言之，通过在体外培养的“人工精子”中精确地将一个标记序列插入到一个特定的蛋白质编码基因的内源中，构建一个细胞文库，其中每个细胞系携带一个特定的蛋白标记。标记后的细胞可以通过注射到卵母细胞中一步转化为标记的小鼠。标记的小鼠文库使全球分析蛋白质表达、定位和复合物成为可能，在体内使用标准的标记基检测方法。截至 2021 年 4 月，GTP 中心已生成 1532 个标记细胞系，其中 277 个已成功通过卵母细胞注射用于产生标记的小鼠。总共 242 个标记的小鼠品系已分发给 3 个国家 15 个区的 32 个研究机构的 66 个研究团队。标记产物资源数据库已建立，并定期在 GTP 网站上发布，供科学家查询和订购。之后，更多关于 GTP 产品的信息，如小鼠繁殖、蛋白质组织表达图谱、已发表文献等，也将陆续在 GTP 网站上发布。GTP 中心将为蛋白质功能研究提供一个标准化的平台，这可能会极大地促进生命科学和临床转化的发展。
