Steatosis and genes regulating fatty acid import, synthesis, and degradation lipid homeostasis in Wt, Gsta4−/−, Ppara−/−, and Ppara−/−/gsta4−/− double-knockout (dKO) mice fed chow or 70% polyunsaturated fat (HF) diets. A: Representative sections of oil red O (ORO)–stained lipid droplets in HF livers. B: Quantitation of ORO staining. C: Distribution of lipid droplet size in Ppara−/− and Ppara−/−/gsta4−/− double-knockout (dKO) mice fed HF diets. D: Fatty acid transport protein (Fatp2) mRNA expression. E: Fatty acid synthase (Fasn) mRNA expression. F: Peroxisome proliferation-activated receptor γ (Pparg) mRNA expression. G: Cyp4a10 mRNA expression. H: Carnitine palmitoyltransferase (Cpt1) mRNA expression. I: Patatin-like phospholipase domain containing 3 (Pnpla3) mRNA expression. Statistical significance was determined by two-way analysis of variance, followed by Student-Newman-Keuls post hoc analysis. Data are expressed as means ± SEM (B and D–I). n = 6 to 8 per group (B and D–I). ∗P < 0.05 for chow (C) versus 70% HF diet (within each genotype); †P < 0.05 (between genotypes for chow diet); ‡P < 0.05, ‡‡P < 0.01 (between genotypes for 70% HF diet). Original magnification, ×20 (A).