1. Graduate School of Pharmaceutical Sciences; University of Tokyo; Tokyo 113-0033 Japan
2. Department of Anatomy and Developmental Biology; Graduate School of Medicine; Chiba University; Chiba 260-8670 Japan
3. BioResource Center; RIKEN; Ibaraki 305-0024 Japan
4. Lipid Metabolism Project; Department of Advanced Science for Biomolecules; The Tokyo Metropolitan Institute of Medical Science; Tokyo 156-8506 Japan
5. CREST; Japan Science and Technology Agency (JST); Tokyo 102-0075 Japan