Inducible expression of cre by human CD34 elements: suppression by tetracycline.

(A) Expression of the cre transgene in the tissue of a double-transgenic mouse (CD34tTA-Tet-O-cre) in the absence of tetracycline. The expression level for liver was used to quantitate relative expression in other tissues as described in the legend to Figure 7. (B) Suppression of cre expression in the presence of tetracycline. A double-transgenic mouse was kept on tetracycline for 5 days before it was killed. The level of Cre RNA in liver in the absence of tetracycline (Figure 7A) was used to quantitate relative cre RNA. Note that the relative scale is approximately 100-fold lower than that in Figure 7A.