Identification de régions génomiques candidates pour le pH ultime de la viande par détection de signatures de sélection et de QTL au sein de lignées divergentes de poulet de chair

The ultimate pH (pHu) is a major determinant of the technological and sensory properties of chicken meat. It seems also to be associated with the development of muscular defects such as White Striping or Wooden Breast. While a strong genetic component of this trait has been demonstrated, genes controlling pHu remain unknown. The aim of the present study was to look for candidate genomic regions by taking advantage of a unique resource population of two divergent lines selected for the breast meat ultimate pH from a commercial fast-growing line. Two complementary approaches were applied: detection of selection signatures at each of the first 5 generations of selection (G1 to G5) and QTL mapping by genome-wide association study at the sixth generation (G6). Thanks to genotyping with the 57K Illumina SNP array of 288 sires from generations G0 to G5, we identified more than one hundred selection signatures. They determined 63 candidate regions, among which some were selected from the first generation and remained significant throughout the selection process. GWAS analysis of 558 phenotyped and genotyped animals revealed 24 QTL regions for breast meat pHu and 10 QTL for thigh meat pHu. Our results indic