Genome-wide association studies of anserine and carnosine contents in the breast meat of Korean native chickens

Histidine-containing dipeptides (HCDs), such as anserine and carnosine, are enormously beneficial to human health and contribute to the meat flavor in chickens. Meat quality traits, including flavor, are polygenic traits with medium to high heritability. Polygenic traits can be improved through a better understanding of their genetic mechanisms. Genomewide association studies (GWAS) constitute an effective genomic tool to identify the significant singlenucleotide polymorphisms (SNPs) and potential candidate genes related to various traits of interest in chickens. This study identified potential candidate genes influencing the anserine and carnosine contents in chicken meat through GWAS. We performed GWAS of anserine and carnosine using the Illumina chicken 60K SNP chip (Illumina Inc., San Diego, CA) in 637 Korean native chicken -red -brown line (KNCR) birds consisting of 228 males and 409 females. The contents of anserine and carnosine in breast meat of KNC-R chickens were investigated. The mean value of the anserine and carnosine are 29.12 mM/g and 10.69 mM/g respectively. The genomic heritabilities were moderate (0.24) for anserine and high (0.43) for carnosine contents. Four and nine SNPs were significantly (P < 0.05) associated with anserine and carnosine, respectively. Based on the GWAS result, the 30.6 to 31.9 Mb region on chicken chromosome 7 was commonly associated with both anserine and carnosine. Through the functional annotation analysis, we identified HNMT and HNMT-like genes as potential candidate genes associated with both anserine and carnosine. The results presented here will contribute to the ongoing improvement of meat quality to satisfy current consumer demands, which are based on healthier, better -flavored, and higher -quality chicken meat.