Fig. 2.

Imaging of mouse PrU cells reveals unique and shared features with prostatic and urethral cells. Scanning electron microscopy (EM) images of PrU cells show a focal region of cells where they appear to be multilayered (A), a region that is not multilayered and displays unique features (B), and a higher magnification of this region (C). The features of distal LumA cells (D), proximal LumP and basal cells (E), and LumP cells at higher magnification (F) are shown for comparison. Arrows indicate basal nuclear orientation (purple), mitochondrial density (red), apical membrane structures (orange), rough endoplasmic reticulum (green), and Golgi apparatus (blue). Scale bars in A–F indicate 5 µm. G–L Immunofluorescence staining show changes in basal and proximal keratin expression. G Overview of the periurethral region with neighboring urethral and proximal cells at low power. Insets show co-expression of basal keratins CK5 (red) and CK14 (green) in distal (H) and proximal (I) basal cells, and consistent CK5 but reduced CK14 in periurethral (J) and periurethral and urethral (K) basal cells. Proximal keratin CK4 (white) is maintained through the proximal and periurethral region (L). No superficial-like cells were observed in the periurethral region. Scale bars in G–L indicate 50 µm