1. Section of Population Genetics and Embryology, Department of Genetics and Biotechnology, Danish Institute of Agricultural Sciences, Tjele, Denmark.
2. Institute of Human Genetics, Aarhus University, Aarhus, Denmark.
3. Beijing Genomics Institute, Beijing, China.
4. Section of Population Genetics and Embryology, Department of Nutrition and Production Physiology, Department of Animal Health, Welfare and Nutrition, Danish Institute of Agricultural Sciences, Tjele, Denmark.