Fig. 4.

B12 and FA deficiency may induce Cyp1a1 mRNA in liver and accumulation of erythroblasts in bone marrow in an AhR-dependent manner. (A–C) B6 mice were fed control, B12-deficient, or FA-deficient diets for 16 wk on wire bottom cages. (A) Serum homocysteine (Hcy) was measured in retroorbital blood by commercial fluorometric kit. After confirming depletion of B12/FA, half of control diet-fed mice were orally administered 10 ng/kg TCDD overnight and all other mice received corn oil. Mice livers and bone marrows were collected and processed the following day. (B) Relative liver Cyp1a1 mRNA measured by RT-qPCR and normalized to Hprt1 and corn oil-treated mice. (C) Proportion of TER119⁺ singlets in bone marrow that are G3 erythroblasts, as determined by flow cytometry. Data are means ± SE (n = 5). *P < 0.05, **P < 0.01 vs. control diet-fed mice assessed by Student’s t test. (D) B6 and AhR-null mice were injected i.p. with corn oil or 2 μg/kg TCDD. After 5 h, livers were processed for analysis. Relative liver Cyp1a1 mRNA was measured by RT-qPCR and normalized to Hprt1 and corn oil-treated mice. Data are means ± SE (n = 2–3). (E and F) B6 and AhR-null mice were fed control or FA-deficient diet for 8 wk on wire bottom cages. (E) Relative liver Cyp1a1 mRNA measured by RT-qPCR and normalized to Hprt1 and control diet-fed mice. (F) Proportion of G3 erythroblasts among TER119⁺ singlets in bone marrow, as determined by flow cytometry. Data are means ± SE (n = 3–4). *P < 0.05 vs. control diet-fed mice assessed by Student’s t test.