Fig. 1.

Stress responses in Magel2-null and control mice. Values represent the mean ± sem; n = 5–8 group. Black bars represent wild-type control, white bars represent Magel2-null. A and B, basal levels of serum corticosterone were elevated in both female and male Magel2-null mice compared with control (Student's t test; *, P < 0.01). Serum corticosterone levels were determined 30 min after restraint stress and compared within sex and genotype to basal levels by Student's t test. As expected, restraint significantly increased corticosterone levels over basal levels in the control mice (4.1 ± 1.1-fold and 2.6 ± 0.6-fold over basal in control male and female mice, respectively, both significantly increased over basal; **, P < 0.001). Restraint also increased corticosterone levels over basal in the Magel2-null mice [2.5 ± 0.3-fold (Magel2-null male) and 1.3 ± 0.1-fold (Magel2-null female) over basal, both ***, P < 0.002 comparing restrained levels with basal levels]. C and D, Serum corticosterone levels were determined 30 min after insulin injection. As expected, corticosterone levels in control mice were elevated, with an average increase of 1.7 ± 0.5-fold (male) and 1.9 ± 0.3-fold (female) over basal levels after 30 min (both sexes #, P < 0.03). An appropriate increase was seen in the male Magel2-null mice (2.0 ± 0.2-fold increase; ##, P < 0.01). However, Magel2-null female mice had no significant (n.s.) change in corticosterone levels after insulin administration.