(A) Scheme illustrating the involved alleles. Binding of doxycycline to the reverse tetracycline-controlled transactivator (rtTA) expressed under the nephrin promotor (Nefta8) leads to expression of a Cre recombinase and excision of a loxP-flanked region in the gene for podocin (nphs2).
(B) Podocin expression at the protein level in isolated glomeruli taken 14 days after end of induction with doxycycline
(C) Glomerular expression of podocin and nephrin as analyzed by immunofluorescence in kidney samples after 14 days. Note that in addition to the deletion of podocin, nephrin expression was also lost. Scale bar: 100 μm.
(D) Light microscopy of the same samples showing protein droplets (arrow) in dilated tubuli of nephrotic mice. Scale bar: 100 μm.
(E) Electron microscopy displayed normal foot processes in the uninduced animals (arrowheads) and foot process effacement indicated by (arrows) in the nephrotic mice. Scale bar: 2 μm.