1. Graduate Institute of Veterinary Medicine, National Taiwan University, National Taiwan University, Taipei 10617, Taiwan
2. School of Veterinary Medicine, National Taiwan University, National Taiwan University, Taipei 10617, Taiwan
3. Department of Medical Research, Mackay Memorial Hospital, Tamshui 251, Taiwan
4. Department of Veterinary Medical Sciences, Graduate School of Agriculture and Life Sciences, The University of Tokyo, Tokyo 113-8567, Japan
5. Department of Biochemistry and Cell Biology, Faculty of Veterinary Medicine, Utrecht University, Utrecht 3584CM, the Netherlands
6. Research Center for Developmental Biology and Regenerative Medicine, National Taiwan University, National Taiwan University, Taipei 10617, Taiwan