Fig. 7. Molecular expression analysis of metanephric mesenchyme-specific Lim1 knockout mutants. Whole-mount in situ hybridization of the metanephros of Rarb2Cre^tg/+; Lim1^flox/+ (A,C,E,G,I,K,M) and Rarb2Cre^tg/+; Lim1^lz/flox (B,D,F,H,J,L,N) embryos at E13.5 with Wnt4 (A-D), Dll1 (E-H), Brn1 (I,J), Wnt9b (K,L) and Bf2 (M,N) probes. (A,B,E,F,K-N) Ventral view of the metanephros. (C,D,G-J) Cryosection of the cortical region of the metanephros. Broken lines indicate renal vesicle; white arrowheads in C and D indicate Wnt4-expressing pretubular aggregate cells that do not form the renal vesicle; black arrowheads in E indicate Dll1 upregulation in differentiated nephron progenitors. np, nephron progenitor; sr, stroma; ub, ureteric bud.