Ana Claudia Carstea, Genetic Reprogramming Group, Agricultural Biotechnology Center, Szent Györgyi A u. 4, H-2100 Gödöllö, Hungary.
World J Stem Cells. 2009 Dec 31;1(1):22-9. doi: 10.4252/wjsc.v1.i1.22.
In mice, gene targeting by homologous recombination continues to play an essential role in the understanding of functional genomics. This strategy allows precise location of the site of transgene integration and is most commonly used to ablate gene expression ("knock-out"), or to introduce mutant or modified alleles at the locus of interest ("knock-in"). The efficacy of producing live, transgenic mice challenges our understanding of this complex process, and of the factors which influence germline competence of embryonic stem cell lines. Increasingly, evidence indicates that culture conditions and in vitro manipulation can affect the germline-competence of Embryonic Stem cell (ES cell) lines by accumulation of chromosome abnormalities and/or epigenetic alterations of the ES cell genome. The effectiveness of ES cell derivation is greatly strain-dependent and it may also influence the germline transmission capability. Recent technical improvements in the production of germline chimeras have been focused on means of generating ES cells lines with a higher germline potential. There are a number of options for generating chimeras from ES cells (ES chimera mice); however, each method has its advantages and disadvantages. Recent developments in induced pluripotent stem (iPS) cell technology have opened new avenues for generation of animals from genetically modified somatic cells by means of chimera technologies. The aim of this review is to give a brief account of how the factors mentioned above are influencing the germline transmission capacity and the developmental potential of mouse pluripotent stem cell lines. The most recent methods for generating specifically ES and iPS chimera mice, including the advantages and disadvantages of each method are also discussed.
在小鼠中，同源重组的基因靶向仍然在功能基因组学的理解中发挥着重要作用。这种策略允许精确地定位转基因整合的位点，并且最常用于消除基因表达（“敲除”），或者在感兴趣的基因座处引入突变体或修饰等位基因（“敲入”）。生产活体转基因小鼠的功效挑战了我们对这一复杂过程的理解，以及影响胚胎干细胞系生殖系能力的因素。越来越多的证据表明，培养条件和体外操作可以通过积累染色体异常和/或胚胎干细胞基因组的表观遗传改变来影响胚胎干细胞（ES 细胞）系的生殖系能力。ES 细胞系的有效性在很大程度上依赖于品系，并且它也可能影响生殖系的传递能力。最近，在生产生殖系嵌合体方面的技术改进集中在提高 ES 细胞系生殖系潜力的方法上。有许多从 ES 细胞生成嵌合体的选择（ES 嵌合体小鼠）；然而，每种方法都有其优点和缺点。诱导多能干细胞（iPS）细胞技术的最新进展为通过嵌合技术从遗传修饰的体细胞生成动物开辟了新途径。本综述的目的是简要说明上述因素如何影响小鼠多能干细胞系的生殖系传递能力和发育潜力。还讨论了最近用于生成特定 ES 和 iPS 嵌合体小鼠的方法，包括每种方法的优缺点。
