Muscle from 285 F2 female and male mice were generated by intercrossing F1 mice. Mice were fed chow diet containing 4% fat (Ralston-Purina Co., St. Louis, MO) until 8 weeks of age and then were placed on a high-fat "Western" diet containing 42% fat and 0.15% cholesterol (Teklad 88137, Harlan Teklad, Madison WI) for 12 weeks. At 20 weeks mice were sacrificed, after a 12-hour fast Muscle tissues were dissected and flash frozen in LN2 and stored at -80°C. Keywords=Genetics of Gene Expression Keywords Keywords=C57B1/J6 Keywords=C3H/HeJ