Fig. 4. Metanephric kidney development in 13.5 and 11.5 dpc embryos. Morphology of representative sagittal H&E stained sections of 13.5 (A-C) and 11.5 dpc (D-E) embryos. At 13.5 dpc, the metanephric kidney is well developed in wild-type embryos (A) and a few homozygous mutant embryos (C). In the majority of mutant embryos, the metanephros is lacking and only remnants of the metanephric mesenchyme (arrow) are visible (B). At 11.5 dpc, the ureteric bud has invaded the mesenchyme and bifurcated once, surrounded by condensed metanephric mesenchyme in wild-type (D) and a few mutant embryos (F). In the majority of mutant animals, only uninduced metanephric mesenchyme is present (E). Ad, adrenal gland; CM, condensed metanephric mesenchyme; M, metanephric mesenchyme; Met, metanephric kidney; UB, ureteric bud. Scale bars: 150 µm in A-C; 50 µm in D-F.