REV-ERBβ-deficient mice exhibit an altered metabolic phenotype and feeding schedule.
(A) Real-time respiratory exchange ratio (RER) monitoring of pre-acclimated male WT (black square) versus REV-ERBβ KO mice (gray circles) using indirect calorimetry. Mice were fed normal chow over a 3 day period. (F(380,4568) = 5.475, p<0.0001). (B) Average RER value, (C) energy expenditure, and (D) infrared activity beam break counts, indicating movement, for day versus night of the mice in panel A. (n = 7 per group). (E) Food intake measurements of male WT (black square) versus male REV-ERBβ KO mice (gray circles) fed normal chow over a 2 day period. (F) Average fasting RER value taken from a 6 hour period during the fast. (n = 7 per group) Data are representative of 2 independent experiments demonstrating similar results. Experiments using female mice demonstrated similar results (data not shown). Values are mean±s.e.m. Average RER was obtained using ANCOVA (analysis of covariance) with ambulatory activity used as a covariate. Statistical significance was assessed using two-way ANOVA or Student’s two-tailed t-tests. * p<0.05, ** p<0.01, *** p<0.005.