Fig. 1.

HF-fed Pemt^−/− mice are hypothermic upon cold exposure. Pemt^+/+ and Pemt^−/− mice (8–9 weeks old) were fed the HF diet for 2 weeks. A, B: Mice were housed individually for 3 days then placed in metabolic cages for metabolic measurements throughout the light and dark cycles. Heat production (A) and physical activity (B) accessed by beam breaks. b.w., body weight. C: HF-induced body weight gain. D: Rectal temperature (Temp.) during cold challenge. Mice were fasted for 4 h then placed at 4°C without bedding, food, or water. All data are from five to six mice of each genotype; *P < 0.05 by Student t-test for Pemt^+/+ versus Pemt^−/−.