Identification of candidate genes for blood metabolites in Iranian chickens using a genome-wide association study

1. In order to identify loci associated with metabolic traits, a genome-wide association study was carried out in a chicken F2 population derived from a reciprocal cross between Iranian Urmia indigenous chickens and Arian broiler line using Illumina 60K Chicken single nucleotide polymorphism (SNP) BeadChip. 2. Six traits including plasma level of triglycerides (TGs), cholesterol (Chol), glucose (Glu), total protein, albumin (Alb) and globulin (Glo) were recorded. The association between the identified SNPs and metabolic traits was estimated by general linear model (GLM) and compressed mixed linear model (CMLM). 3. A total of 38 SNPs were identified at the genome-wide significant and suggestive levels, of which 5 SNPs reached a 5% Bonferroni genome-wide significance (P < 2.58E-6) for TG, Alb and Glo through CMLM, and 21 SNPs were significantly associated with TG, Chol, Glu, Alb and Glo through GLM. 4. Gene ontology showed that these SNPs were located within or near the candidate genes responsible for metabolic traits. 5. In conclusion, the identified candidate genes provided novel information for molecular mechanisms underlying metabolic traits. These findings are important in marker-assisted selection in the chicken breeding scheme.