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

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.