Fig. 3. Expression of Sgk is dependent on Hoxd gene function in genitals and forelimb buds. (A) Sgk expression appears distally in E11 wild-type limb buds. At E12.5 and E13.5, expression is prominent in the proximal portion of the interdigital zone. By contrast, Sgk expression in mutant HoxD^Del1-13 limbs is largely limited to a proximal domain at E12.5, with little interdigital staining. (B) In the developing genital bud, Sgk is expressed in a distal domain of the ventral mesenchyme, adjacent to the urethral epithelium (arrow). This domain is not visible in mutant genital buds. (C) Real-time RT-PCR measurements mirror the WISH results, with highly significant (^**P<0.01) differential expression in both limbs and genitals. Although the differential expression was initially detected in genitals, the highest fold change in the developmental series was measured in limbs (2.36-fold at E11.5).