Figure 4

Y chromosome FISH detection of mutant BM-derived cells and the epithelial marker LTA in the kidney. (A- H) Conventional fluorescence micrographs show bone marrow-derived, PKD mutant cells as detected by the presence of a Y chromosome (green). Sections are costained with LTA as marker for the proximal tubule (red) and DAPI for nuclei (blue). (A and B) Male control kidney shows a Y chromosome signal in most cells (A) which is diffuse in the tubules (B, white arrows) and more compact in interstitial cells (B, yellow arrows). (C) A low power field from the kidney of a female transplanted with mutant male bone marrow showing several Y chromosome positive cells, some of which are associated with the tubule (arrows). (D-H) Examples of Y chromosome positive cells that could be interpreted as proximal tubule epithelial cells, but could equally be attributed to Y chromosome signals in the nuclei of infiltrating and overlaying non-epithelial cells as depicted by dashed lines in inserts. Scale bar in A = 50μm; C is at the same magnification as A. Scale bar in B = 20 μm; D-H are at the same magnification as B. Insets are at an additional 2X zoom.