Figure 2.

Rhophilin-1 is expressed in podocytes of mature glomeruli of newborn mice. (A) Rhophilin-1 is not expressed in cells of immature outer cortical glomeruli that stain positively for WT1, an early marker protein of the podocyte lineage (arrowheads). Rhophilin-1 expression is restricted to podocytes of late-stage capillary loop glomeruli located more centrally in the kidney. The peripheral edge of the newborn kidney cortex is located at the top left. (B and C) Rhophilin-1 partially colocalizes with nephrin in mature glomeruli. Note that nephrin expression spatiotemporally precedes that of Rhophilin-1 as the podocytes differentiate and foot processes are formed in maturing glomeruli. Arrowheads indicate nephrin-expressing podocytes that are negative for Rhophilin-1. Arrows highlight glomerular expression of nephrin in podocytes as they enclose around capillary loops before Rhophilin-1 expression is initiated. DAPI, 4′,6-diamidino-2-phenylindole. Scale bars, 50 μm in A and B; 20 μm in C.