消化道细胞表达Cre重组酶转基因小鼠的功能鉴定

Expression of Cre Recombinase in Gastrointestinal Tissues of Albumin-Cre Transgenic Mice

目的:检测白蛋白启动子介导的Cre重组酶转基因小鼠Alb-Cre-2中Cre重组酶的组织分布及其在体内介导基因重组的作用。方法:将Alb-Cre小鼠与Smad4条件基因打靶小鼠交配,利用PCR对Cre重组酶介导重组的组织特异性进行检测;然后,将Alb-Cre-2转基因小鼠与ROSA26报告小鼠交配,利用LacZ染色对双转基因阳性子代小鼠进行检测。结果:PCR结果显示心、肺、胰、脑及消化道中Cre重组酶介导的Smad4基因发生重组;LacZ染色进一步表明Cre重组酶在肝细胞、胃壁细胞、空肠潘氏细胞、回肠杯状细胞、大肠杯状细胞、大肠柱状细胞及空泡细胞中特异性表达,并介导ROSA位点LoxP序列间的重组。结论:Alb-Cre-2转基因小鼠在消化道中具有一定的组织特异性,只在胃壁细胞、空肠潘氏细胞、回肠杯状细胞、大肠杯状细胞,大肠柱状细胞及空泡细胞等细胞类型中特异性表达,并能在体内成功地介导这些消化道上皮细胞基因组上LoxP位点间的重组,是一种研制在消化道特定细胞中特异性基因剔除小鼠的良好工具小鼠。

Objective： To identify the tissue distribution and the Cre recombinase activity in the albumin-specific Cre transgenic mouse line（albumin-Cre-2） expressing the Cre recombinase under the control of a mouse albumin gene promoter. Methods： Firstly, the albumin-Cre-2 transgenic mice were bred with mouse strains carrying the conditional targeted Smad4 alleles. Cre mediated recombination in different tissues of the double transgenic offspring was determined using genomic PCR. Secondly, the albumin-cre-2 transgenic mice were bred with ROSA26 reporter strain. The activity of Cre recombinase was revealed by LacZ staining in the albumin-Cre and ROSA26 double transgenic mice. Results： PCR results revealed that the Smad4 gene was deleted by Cre mediated recombination in the gastro-intestinal tissues, liver, lung, pancreas and brain. LacZ staining of the albumin-Cre and ROSA26 double transgenic mice showed that Cre recombinase activity was detected in hepatocytes, gastric parietal cells, jejunum paneth cells, ileum goblet cells and also colon mucosa cells. Conclusion： All these data indicated that the Cre recombinase has been expressed in the liver and gastrointestinal tissues of the albumin-Cre-2 transgenic mice. The mice generated could serve as a useful tool for generating gastrointestinal specific gene-knockout mice.