Fig. 3.

VMC lineage-specific inactivation of Pbx1 does not affect nephrogenesis. (A-J) Control Pbx1^f/+;Foxd1^GC/+ and mutant Pbx1^f/f;Foxd1^GC/+ kidneys at E11.5 (A,B), E16.5 (C,D) and E18.5 (E-J) assayed by IF for the detection of Pax2⁺ renal epithelial progenitors (A-D), E-cadherin⁺ (Cdh1 – Mouse Genome Informatics) renal epithelia (A-H); podocalyxin⁺ glomerular podocytes (C,D,G,H); calbindin-28K⁺ distal nephron segments (E,F); and villin⁺ proximal tubules (I,J). Scale bars: 50 µm. At E11.5 (A,B) both mutant and control kidneys are characterized by a T-shaped ureteric bud surrounded by nephrogenic mesenchyme, and by E16.5 (C,D) extensive ureteric bud branching and expansion of the nephrogenic progenitor population can be seen in both genotypes. At E18.5, differentiated glomerular (G,H), proximal (I,J) and distal (E,F) nephron segments are detected in both mutant and control kidneys. (K) Although mutant kidneys exhibit well-differentiated nephrons and cortical-medullary patterning, they are ∼30% smaller than controls as determined by quantitative measurement of midsagittal area at P0. (n=8 per genotype; error bars represent s.d.). See also supplementary material Fig. S3.