Figure 3.

Identification and characterization of compound Pkd2-null mice with a human PKD2 transgene (Pkd2^−/−;PKD2^tg). A: cDNAs transcribed from the total RNA of 1-month-old Pkd2^−/−;PKD2^tg and age-matched wild-type (WT) kidneys were used for RT-PCR with a pair of mouse Pkd2 cDNA primers. A positive band is observed in wild-type, but not in Pkd2^−/−;PKD2^tg, mice. B: Similar RT-PCR analyses were performed with a pair of human PKD2 cDNA primers. A positive band is seen in the Pkd2^−/−;PKD2^tg, but not the wild-type, kidneys. C: The same RT-PCR results are obtained in liver. Glyceraldehyde-3-phosphate dehydrogenase (GAPDH) mRNA was used as a loading control. D: Western blot analyses of organs/tissues of 1-month-old wild-type and Pkd2^−/−;PKD2^tg mice using the anti-polycystin (PC)-2 antibody (hPKD2-Cp). PC2 is detected in the kidney, liver, and pancreas of Pkd2-null mice with human PKD2 transgene. β-Actin was used as a loading control. E: Quantitative analyses of the Western blot results show that PC2 expression is significantly higher than in the wild-type organs. IHC analysis (IHC) (F and G) and immunofluorescence (IF) (L and M) staining with the hPKD2-Cp antibody to detect PC2 in the kidneys of 1-month-old wild-type and Pkd2^−/−;PKD2^tg mice. Stronger positive staining (arrows in F, L versus G, M) is seen in the Pkd2^−/−;PKD2^tg kidney than in the age-matched wild-type kidney. IHC (H–K) and IF (N–Q) staining analyses were used for examine the liver and pancreas of these mice. All results are similar to the kidneys' staining (arrows in H, N versus I, O and J, P versus K, Q). R: Kaplan-Meier survival analysis of wild-type and Pkd2^−/−;PKD2^tg mice. The median survival rate of the Pkd2^−/−;PKD2^tg mice was around 6 months. n = 25 (R, per genotype). Data expressed as means ± SD (E). Scale bars: 50 μm (F–K); 100 μm (L–Q). M, marker.