建立对未分化细胞特异性标记的小鼠胚胎干细胞系

构建pRex-1-EGFP表达载体，电穿孔转染小鼠ES细胞，用增强绿色荧光蛋白对起源于3．5d胚泡内细胞团的小鼠胚胎干细胞进行特异性标记，用荧光显微观察EGFP的表达以及RT-PCR方法检测Rex-1基因在未分化和分化中ES细胞中的表达情况。结果显示，EGFP基因成功转入小鼠ES细胞，并在未分化的ES细胞中高效表达；细胞开始分化后，EGFP的表达开始下降。由Rex-1基因启动子控制下的EGFP稳定表达的小鼠ES细胞系，对哺乳动物早期发育过程的研究以及对筛选能够调节上述过程的小分子化合物具有重要意义。

Establishing Mouse Embryonic Stem Cell Line Carrying a Fluorescent Undifferentiated Marker

To label mouse ES cells,a cell line derived from the inner cell mass of 3.5-day blastocysts,with enhanced green fluorescent protein (EGFP),the vector of pRex-1-EGFP was transferred into mouse ES cells by electroporation.The expressions of Rex-1 in undifferentiated and differentiated ES cells were detected by the microscopic observation of EGFP and by RT-PCR.The results showed that the EGFP gene was transferred into the mouse ES cell line,and the transfected cells in undifferentiated state showed high levels of EGFP expression.When the cells began to differentiate,the EGFP expressions were gradually reduced.A mouse ES cell line expressing EGFP under the control of Rex-1 gene promoter was generated.The cell line provides a powerful approach for the research of the process of mammalian development and for the screening of small molecules that can regulate this process.