Characterization of the PRCP hypomorph (PRCP^gt/gt) mouse. (A) Total renal mRNA was reverse-transcribed to cDNA from C57BL/6 (WT) and PRCP^gt/gt (gt/gt) mice, and quantitative PCR was performed. Data represent mean ± SEM of PCR studies from 3 mice in each group. (B) PRCP antigen level was detected by immunoblot with a goat antimouse-PRCP antibody (anti-TND-20) on 100 μg of renal lysate from WT or PRCP^gt/gt mice. Anti-GAPDH antibody was used as a loading control. (C) Comparative antigen levels from panel B were quantified with densitometry. The bar graph is the mean ± SEM ratio of PRCP/GAPDH antigen in 4 WT or PRCP^gt/gt renal lysates. (D) Longitudinal sections of X-Gal–stained whole mouse kidney from WT and PRCP^gt/gt (gt/gt) mice. Kidney sections were stained for LacZ with X-Gal to determine the presence of the CD4TM-β-geo transgene in place of the Prcp gene. Blue LacZ staining in the PRCP^gt/gt indicates where endogenous PRCP would be expressed in these tissues from WT mice. The photographs were taken on a Nikon SMZ-U dissecting microscope at 2× magnification. (E) Cross section of X-Gal–stained renal cortex from a PRCP^gt/gt mouse showing a Bowman capsule of a glomerulus with LacZ protein and variably darkly stained tubules. The black arrow points to a darkly stained tubule. (F) Longitudinal vessel sections from renal cortex from a PRCP^gt/gt mouse showing staining for the LacZ protein, which replaces PRCP.¹⁴  The figure is at 40× magnification. Black arrow points to vascular PRCP as indicated by the presence of LacZ. (E-F) Photographed on an Olympus BH-2 microscope aperture 0.70 160/0.17 at 40×. Arterial PRCP was colocalized with the endothelial cell marker PECAM (CD31; G) and the vascular smooth muscle cell marker α-smooth muscle actin (α-SMA; H). (G-H) Photographed on a Zeiss LSM510 confocal microscope aperture 40×/1.3 oil immersion. *P < .05.