Capsular layer is thickened in Mrap−/− mice. A, B) Representative images of Mrap−/− adrenal glands and of wild-type littermates showing increased capsule thickness (A; highlighted with black bars) and in response to lifetime GC treatment (B). The bottom panels show digital magnification of the adrenal gland at the capsular layer. C) Capsular layer measurements (micrometers) of the adrenals of the Mrap−/− mice compared with the wild-type mice and in response to lifetime corticosterone replacement. D) Shh expression in the adrenal gland of male Mrap+/+ (n = 6) and Mrap−/− (n = 6) mice and of the animals after lifetime corticosterone replacement (GC) (Mrap+/+, n = 4; Mrap−/−, n = 5) shows an increase in Shh expression in Mrap−/− mice. E, F) In situ hybridization demonstrated expression of Shh outside ZG in the adrenals of Mrap−/− mice (E) and in the animals after lifetime corticosterone replacement (GC) (F). CX, cortex; M, medulla. Scale bars, 50 µm. One-way ANOVA with Bonferroni multiple comparison testing. *P < 0.05, **P < 0.01, ***P < 0.001. Ns, not significant.