1. Institut National de la Recherche Agronomique (INRA, UR83) Recherches Avicoles, Nouzilly
2. INRA, ENVT, UMR444 Génétique Cellulaire, Castanet-Tolosan
3. INRA, UMR1313 Génétique Animale et Biologie Intégrative, Jouy-en-Josas, France
4. Department of Animal and Avian Sciences, University of Maryland, College Park, Maryland
5. Department of Animal and Food Sciences, University of Delaware, Newark, Delaware
6. Department of Poultry Science, University of Georgia, Athens, Georgia