1. Division of Animal Sciences; Department of Agricultural and Food Sciences (DISTAL); University of Bologna; Viale Fanin 46 40127 Bologna Italy
2. Centre for Genome Biology; University of Bologna; 40126 Bologna Italy
3. INRA; UR631; SAGA; CS52627 31326 Castanet Tolosan France
4. INRA; UE 1372; GenESI; Le Magneraud; BP52 17700 Surgères France