Supplemental Figure S6.

Ectopic Sox9 expression in proximal tubule–derived cystic segments with reduced or absent lotus tetragonolobus lectin (LTL) staining in P1 Six2crePkd1 knock-out (KO) kidneys. A and B: Representative co-immunofluorescence images for Sox9 (red) and LTL (green) in P1 control and Six2crePkd1KO kidneys (A). In controls, Sox9 was present in early epithelial nephron derivatives (arrow), but was absent in LTL-positive proximal tubules (arrowhead). B: In Six2crePkd1KO kidneys, Sox9 is expressed ectopically in cystic tubules that have reduced or absent LTL staining (concave arrowheads), but is absent in tubules with robust LTL staining (arrowhead). Scale bar = 50 μm.