Fig 1: Folic acid and one-carbon donor availability regulate liver mitochondrial and lipid homeostasis. (A) Methylenetetrahydrofolate reductase (MTHFR) and (B) mitochondrially encoded cytochrome c oxidase II (MT–CO2) in livers of glycine N-methyltransferase (GNMT) knockout (KO) and wild-type (WT) mice fed a control (CON) or folate-supplemented (FS) as determined by immunoblotting with a (C) representative immunoblot (arbitrary units; n = 6–8 per group). (D) Liver succinate dehydrogenase subunit A (SDHA), (E) cytochrome c oxidase subunit 4 (COXIV), and (F) MT–CO2 in livers of WT mice receiving a high-fat diet (HF) and or a serine/glycine-deficient HF diet (-SG) as determined by immunoblotting with a (G) representative immunoblot (arbitrary units; n = 7–8 per group). (H) Liver phospholipids, (I) diacylglycerides, and (J) triacylglycerides (μg/mg; n = 7–8 per group). Data are presented as mean ± SEM. ∗p < 0.05. ∗∗p < 0.01. ∗∗∗p < 0.001.