体细胞基因打靶制备动物乳腺生物反应器的策略与应用

在转基因动物研究中，由于基因表达调控元件的人工拼接和外源基因在动物基因组中随机整合所带来的“位置效应”，致使转基因动物外源基因的表达水平不高并且差异较大。为此，利用定位整合优势，对以基因同源重组为基础的基因打靶技术进行了大量研究。介绍了就利用体细胞基因打靶和核移植技术制备动物乳腺生物反应器的策略和应用情况做一综述，并对提高基因打靶效率的各种策略，打靶细胞的选择，转基因细胞核移植的低融合事件以及基因打靶制备乳腺生物反应器的优越性进行分析。

Production of Mammary Gland Bioreactor by Gene Targeting of Somatic Cells

Producing mammary gland bioreactor showed great advantage over many years, but the level of transgenic expression was low in transgenic animals and the diversity was more great because of the position effect of transgene and the artificial recombination of the gene elements. Gene targeting based on the principle of gene homologous recombination had been studied and applied, because the transgene could be integrated precisely in the chromosome. This review summary the current status of producing mammary gland bioreactor by the technology of gene targeting and nuclear transfer using the somatic cell lines. These aspects were discussed, including the characteristic and difficulties of gene targeting, the strategies to improve the efficiency of gene targeting, the different features of between the strategy of promoter-trap and the Cre-LoxP system, etc; for the others, how to select the cell lines with the different strategies of gene targeting , how to raise the times of cell lines that was cultured after the gene targeting. Somatic cell nuclear transfer offers new and exciting opportunities in the areas of the gene targeting. However, the field as a whole is still difficult and complex. In this paper, we described recent advances and novel approaches, which resulted in progress during the last year. Key problems hindering further progress are addressed, for example, how to increase the efficiency of nuclear transfer. With the technology of gene targeting and nuclear transfer, it should provide a general way to produce specific genetic changes in several mammalian species. We are clearly at the dawn of a new era in mammalian genetic technology.