TCF/Lef:H2B-GFP reporter gene expression during kidney development. (A) Widefield fluorescent dorsal view of the urogenital tract at E12.5. Widefield fluorescent view of the kidney and suprarenal gland at E14.5 (B) and P2 (C). (D) Expression in the kidney is restricted to the collecting ducts. (E) Mesonephric and paramesonephric ducts positive for the transgene at E14.5. (F) Transverse section through the suprarenal gland showing high levels of the transgene in the cortical region at P2. (G) Detail of the renal cortex at P2 showing a branching event. High magnification images of the kidney (H) and adrenal cortex (I) at P21. Yellow arrowhead marks Wolffian duct, white arrowhead marks Müllerian duct. ag, adrenal gland; g, gonad; k, kidney; Md, Müllerian duct; Wd, Wolffian duct.