Serum lipids change in ClockΔ19 mice. Diurnal profiles of cholesterol (A), TGs (B), FFAs (C), and glycerol (D) in the serum of wild-type (WT; closed circles) and ClockΔ19 (open circles) mice in DD (n = 3/time point). Time points indicate hours spent in DD after the last lights off. Diurnal profiles of FFAs (E) and glycerol (F) in the serum of wild-type (closed circles) and ClockΔ19 (open circles) mice in LD conditions (n = 3–5/time point). Time-of-day dependent variations in serum FFA and glycerol levels in WT (black bars) and Bmal1−/− (white bars) animals kept in DD (n = 3–5/time point). All data are shown as means ± SEM. *P < 0.05; **P < 0.01; ***P < 0.001 by two-way ANOVA with Bonferroni posttest.