Figure 3. Tak1 and Jun are required for self-renewal of NPCs throughout nephrogenesis.

(a,b) H&E staining of P0 Tak1^het, Tak1^NPC, Jun^het and Jun^NPC kidneys. Scale bars, 500 μM (c) Kidney sizes. Number of mice (n) analysed per group is noted in the graph. **P<0.005, Student's t-test. (d,e) Transcriptional analysis of Tak1, Jun, Myc and cap mesenchyme markers in NPCs isolated from E17.5 Tak1^het, Tak1^NPC and E14.5 Jun^het, Jun^NPC kidneys. Error bars represent s.d. Two biological replicates analysed per genotype, n=2. (f) MYC immunostaining of E14.5 Jun^het and Jun^NPC kidneys. Scale bars, 50 μM. (g) H&E and co-immunostaining of SIX2 (green, cap mesenchyme) and DBA lectin (red, collecting duct) of P0 Tak1^NPC and Jun^NPC kidneys. Scale bars, 25 μM. (h) Average number of SIX2+ NPCs per kidney section per genotype. Error bars indicate s.d. **P<0.005, Student's t-test. (i) Ki67 (green) and SIX2 (red) co-immunostaining of P0 Tak1^het, Tak1^NPC, Jun^het, Jun^NPC kidneys. Insets show magnifications of cap mesenchymes with arrows pointing to Ki67+ cells. Scale bars, 100 μM. (j) Number of SIX2+/Ki67+ cells per kidney section. Error bars represent s.d. and **P<0.005, Student's t-test (k) β-galactosidase (red) and SIX2 (green) co-immunostaining of E17.5 Tak1^het (Six2^+/cre;Tak1^+/c;R26RLacZ) and Tak1^NPC (Six2^+/cre;Tak1^c/c;R26RLacZ) kidneys. Three mice were analysed per genotype at E14.5 and E17.5 (n=3). CD, collecting duct; CM, cap mesenchyme; PTA, pre-tubular aggregate.