Figure 6.

HIF-2α expression in kidney. (A) E13.5 metanephros from a HIF2α^+/− stained for β-galactosidase histochemistry shows a branching, vessel-like pattern. (B) E14 HIF2a^−/− kidney showing β-galactosidase reaction product in glomerular endothelial cells migrating into the vascular cleft (VC), and in capillary loop stage glomeruli (G). Also, small arrows denote individual cells in the metanephric mesenchyme also containing β-galactosidase. (C) The same slide in B was also labeled with the lectin, BsLB4, an endothelial marker. (D) Co-localization of β-galactosidase and BsLB4 shows complete overlap. (E) Comma-shaped nephric figure from newborn mouse showing HIF2α/LacZ expression by developing podocytes (*). (F) View of newborn mouse showing widespread expression of HIF2α/LacZ in vascular endothelial cells and glomeruli. (G) Boxed region from (F) is shown at higher power. Note HIF2α/LacZ expression in some (arrows) but not all podocytes (arrowheads). (H) Frozen section of a 4 week HIF2α^+/− mouse showing intense β-galactosidase product in an endothelial pattern, and in smooth muscle cells of arteries (arrowhead). (I) Frozen section of a 4 week HIF2α^+/− mouse showing a small artery. Reaction product is seen in both endothelial cells (arrow) and smooth muscle cells (arrowheads). (J) Vascular endothelial cells (arrow) are positive for HIF2α/LacZ and a few tubular epithelial cells (arrowhead) also express HIF2α/LacZ. Reproduced with permission (ref. ⁷⁶).