Fig. 1. Cited2 acts in the adrenogonadal primordium (AGP) to promote adrenal cortex development. (A) Adrenal cortex differentiation is markedly impaired in Cited2 mutant mouse embryos. Urogenital regions from wild-type (WT) or mutant embryos (Mut) were subjected to whole-mount in situ hybridisation (WISH) for Sf-1 or Hoxb9 expression and sectioned. Arrowhead, position of the adrenal anlagen; arrow, Sf-1 expression in the developing gonad; DA, dorsal aorta. (B) Neural crest migration to the adrenal anlagen occurs at E13. Neural crest migration to the adrenal anlagen (arrowhead) was evaluated by double WISH for Cyp11a1 (orange) and Mash1 (purple). The lower left panel shows a section (taken at the line in the top panel) through the adrenal anlagen. (C) Neural crest migration is only mildly affected in Cited2 mutant embryos. WISH for Mash1 or tyrosine hydroxylase (Th) at E13.5 shows that neural crest cells still migrate to the presumptive adrenal area (arrowhead) of mutant embryos, albeit in reduced numbers. (D) Cited2 is expressed in the AGP and the adrenal cortex anlagen. Cited2 mRNA is expressed in the genital ridge (arrow) and the presumptive adrenal area (arrowhead) at E10.5. At E12 (left panel shows WISH; right panel shows section of WISH sample at the white line), expression in the gonad (G) is barely detectable but Cited2 is present in the adrenal anlagen (arrowhead). At E13.5, Cited2 is faintly expressed in the gonads of both sexes. At E14.5, Cited2 is strongly expressed in the cells of the adrenal cortex (C) and weakly expressed in the medulla (M).