Fig. 3.

Expansion and delayed regression of FAdE-expressing cells in adrenals of young Dax1 knockout mice compared with wild type. (A) FAdE activity is maintained in Dax1 KO mice during early developmental stages as shown by immunostaining for β-galactosidase to detect LacZ expression (upper panel, E17.5; lower panel, P7). (B) LacZ expression colocalizes with the fetal zone marker 20αHSD and is found in the inner rim of the 20αHSD-expressing zone at the age of P16 (lower panel). (C) Immunostaining with LacZ and 20αHSD in wild-type and Dax1 KO male mice at P16 (left panel) and P90 (right panel). Although Dax1 KO mice have more FAdE-positive cells at a young age, those cells and the fetal zone regress by 3 months of age. Scale bars: 500 µm.