|Animals and tissue collection.|
C57BL/6J ApoE−/− (B6.ApoE−/−) were purchased from Jackson Laboratory (Bar Harbor, Maine, United States). C3H/HeJ ApoE−/− (C3H.ApoE−/−) were generated by backcrossing B6.ApoE−/− to C3H for ten generations. F1 mice were generated from reciprocal intercrossing between B6.ApoE−/− and C3H.ApoE−/−, and F2 mice were subsequently bred by intercrossing F1 mice. A total of 334 mice (169 female, 165 male) were produced. All mice were fed Purina Chow containing 4% fat until 8 wk of age and then transferred to a “Western” diet containing 42% fat and 0.15% cholesterol for 16 wk. Mice were sacrificed at 24 wk of age. At death, livers were immediately collected and flash-frozen in liquid N2, and gonadal fat pads were extracted and weighed.