1. College of Medical, Veterinary and Life Sciences (MVLS); IBAHCM; University of Glasgow; Garscube Estate, Bearsden Road, Glasgow G61 1QH Scotland UK
2. Sir Henry Wellcome Functional Genomics Facility; Joseph Black Building, University of Glasgow; Glasgow G12 8QQ Scotland UK
3. Roslin Institute and Royal (Dick) School of Veterinary Studies; University of Edinburgh; Roslin Easter Bush, Midlothian EH25 9RG Scotland UK
4. Lohmann Tierzucht; P.O. Box 4602, 7454 Cuxhaven Germany