Figure 2.

Generation and characterization of homozygous human PKD2 transgenic mice (PKD2^tg/tg). A: Mating strategy. Male and female hemizygous PKD2 transgenic mice (PKD2^tg) were mated to generate PKD2^tg/tg mice. PKD2^tg/tg mice were determined by genotyping the offspring from mating pairs of candidate PKD2^tg/tg and wild-type (WT) mice; all of the offspring were expected to have been PKD2^tg positive. B: The candidate PKD2^tg/tg mice were then confirmed by performing quantitative PCR of the tail genomic DNA with human transgene primers and comparing the results to age-matched wild-type and PKD2^tg mice. The ratio of the copy number of PKD2 to glyceraldehyde-3-phosphate dehydrogenase (GAPDH) is over 0.75 in PKD2^tg/tg mice, but below 0.6 in PKD2^tg mice. Wild-type mice were used as a negative control. C: Human PKD2 mRNA expression in different organs/tissues of PKD2^tg (dark gray bars) and PKD2^tg/tg (light gray bars) mice, determined by quantitative PCR analysis. The PKD2 mRNA expression level of PKD2^tg/tg mice is almost as twice that of the PKD2^tg mice (n = 3 per genotype). D: Polycystin (PC)-2 levels in different organs/tissues of PKD2^tg and PKD2^tg/tg mice, determined by Western blot analyses with the anti-PC2 antibody (hPKD2-Cp). β-Actin was used as an internal loading control. E: Quantitative analysis of the Western blot results. F–Q: IHC analysis (F–K) and immunofluorescence (L–Q) staining with the hPKD2-Cp antibody in the kidney, liver, and pancreas shows much higher PC2 labeling in 12-month-old (12M) PKD2^tg/tg mice than in age-matched PKD2^tg mice (arrows) (F, L versus G, M, H, N versus I, O and J, P versus K, Q). R–T: Histological analysis reveals no obvious cysts in these samples. n = 9 (B, WT); n = 18 (B, PKD2^tg); n = 20 (B, PKD2^tg/tg). Data expressed as means ± SD (C and E). Scale bars: 50 μm (F–K); 100 μm (L–Q and boxed areas of R–T); 500 μm (R–T). M, month; qPCR, quantitative PCR.