Abstract：High abundance and tissue-specific gene expression are important for gene therapy and preparation of transgenic animals. Cre-LoxP system is effective to improve transcriptional activity of tissue-specific promoter. However, it is not known if the Cre-LoxP system affects the tissue-specific expression regulated by the specific promoter.. In this study, intestinal mucin 2 promoter was used to regulate the Cre recombinase expression base on Cre-LoxP system. Then luciferase activity was detected after transfection. The results showed that Cre-LoxP system increased the expression of mucin 2 promoter -mediated target genes (6-fold) in intestinal cells. However, cell-specific tests showed that the system decreased the specificity of mucin 2 promoter. The results suggest that the use of Cre-LoxP system requires higher specificity of the promoter although the system can significantly improve the weak promoter activity.
