Sheep anti mouse or donkey anti rabbit hrp conjugated secondary antibody

Whole kidneys (from E12.5 to adulthood) were dissected and then lysed in RIPA buffer (Pierce) supplemented with protease inhibitor cocktail (Roche) and phosphatase inhibitor cocktail (Roche). Lysates were loaded and run on the 12% polyacrylamide gel (Bio-Rad) in 5× Laemmli sample buffer and transferred to a nitrocellulose membrane (GE Healthcare). The membrane was blocked for 1 h in PBST containing 5% milk and subsequently probed with primary antibodies overnight at 4 °C. After 1-h incubation with sheep anti-mouse or donkey anti-rabbit HRP-conjugated secondary antibody (GE Healthcare), the protein level was detected with standard ECL reagents (Thermo Scientific). Antibodies used: anti-α/β-tubulin (1:1000, Cell Signaling, #2148), anti-Lin28a (1:1000, Cell Signaling, #3978), anti-Lin28b (1:1000, mouse preferred) (Cell Signaling, #5422), anti-Six2 (1:1000, Proteintech Group, #11562-1-AP). Uncropped scans included in Supplementary Figure 10.