Table 1.

Expression of Pkhd1 transgenes in the kidney and extrarenal tissues

Transgene	Founders Analyzed	Kidney Expression	Extrarenal Expression
2.0/lacZ	8	5	0
2.0m/lacZ	8	0	0
4.7/lacZ	11	4	1
Pkhd1/Cre	7	3	2

The first column shows the names of the transgenes. The second column shows the numbers of independent founders that were generated for each transgene. The third and fourth columns show the numbers of founders that expressed the transgene in the kidney and extrarenal tissues, respectively. Sixty-two percent of the founders carrying the 2.0/lacZ transgene showed expression in the kidney. In contrast, no founders carrying the same transgene with a mutated hepatocyte nuclear factor-1β-binding site (2.0m/lacZ) showed expression. This difference was statistically significant (P = 0.026 by Fisher's exact test). Only mice carrying the 4.7-kb polycystic kidney and hepatic disease 1 (Pkhd1) fragment (4.7/lacZ and Pkhd1/Cre) showed expression of the transgene in the liver and other extrarenal tissues.