Fig. 4. Ectopic steroidogenic cells are clustered at the anterior region of the Wnt4^-/- gonad. Whole-mount in situ hybridisation for 3ß-hydroxysteroid dehydrogenase (3ß-HSD) expression was performed on gonads and mesonephric region from Wnt4^+/+ or Wnt4^-/- XX 12.5 dpc embryos as indicated. The top panels show the area within the urogenital region where the adrenal forms, which is indicated by the arrows. The asterisks indicate the anterior region of the gonad where the ectopic steroidogenic cells are found in the Wnt4^-/- embryos. The position of the gonad is marked `g'. In all images, anterior is leftwards.