Mapping QTL for white striping in relation to breast muscle yield and meat quality traits in broiler chickens

White striping (WS) is an emerging muscular defect occurring on breast and thigh muscles of broiler chickens. It is characterized by the presence of white striations parallel to the muscle fibers and has significant consequences on meat quality. If its etiology remains unknown, recent studies showed moderate to high heritability values of WS, which emphasized the role of genetics in its determinism. The aim of this study was to identify the first QTLs for WS as well as breast muscle yield and meat quality traits by taking advantage of two divergent lines of chickens selected for meat quality through Pectoralis major ultimate pH (pHu) and which exhibit the muscular defect. In order to better understand the molecular mechanisms associated to WS, an eQTL detection was performed for some candidate genes either suggested by genome-wide association study (GWAS) or based on their biological function. Forty-two SNPs associated with WS, breast yield and meat quality traits were identified. They defined 18 QTL regions located on 13 chromosomes. These results were in favor of a polygenic determinism of the studied traits and suggested a few pleiotropic regions. A set of 16 positional and functional candidate genes was designed for further eQTL detection. A total of 132 SNPs was associated with molecular phenotypes and defined 21 eQTL regions located on 16 chromosomes. Interestingly, several co-localizations between QTL and eQTL regions were observed (on GGA4, GGA5, and GGGA17) which could suggest causative genes and gene networks involved in the variability of meat quality traits and breast meat yiel