All results are expressed as mean ± S.E.M. Statistical significance of differences among groups was determined by Student’s t-test or ANOVA with post hoc analysis, Student-Newman-Keuls using Sigma Stat (SPSS Inc., Chicago, IL). Differences at P < 0.05 were considered statistically significant (*, P < 0.05 vs. WT or control; #, P < 0.05 vs. WT, HFD). Following numbers of mice/samples were used for comparison; Body weight measurement for Irx3 mice (ND, WT/KO: n = 32/25; HFD, WT/KO: n = 12/7) and EnR-Irx3 mice (control/mutant: n = 9/12); Body composition analysis for Irx3 mice (ND WT/KO: n = 21/12; HFD WT/KO: n = 8/5) and EnR-Irx3 mice (control/mutant: n = 9/12); Glucose tolerance test for Irx3 mice (ND 8wk, WT/KO: n = 8/5; ND 18wk, WT/KO: n = 10/6; HFD 18wk, WT/KO: n = 12/7) and EnR-Irx3 mice (control/mutant: n = 5/8); Insulin tolerance test for Irx3 mice (WT/KO: n = 12/7); Indirect calorimeter analysis for Irx3 mice(ND WT/KO: n = 7/5; HFD WT/KO: n = 8/4) and EnR-Irx3 mice(control/mutant: n = 5/7), and Gene expression analysis for Irx3 mice (WT/KO: n = 10/7) and EnR-Irx3 mice (control/mutant: n = 5/7).
