Polymorphism of the melanocortin receptor gene and its association with egg production traits in Lohmann Brown chickens

The melanocortin gene (MC4R) was proposed as a candidate gene in this study for egg production traits (yield and weight) in Lohmann Brown hens. Two different primers from MC4R gene (MC4R-1 and MC4R-2) were investigated. DNA from blood samples was extracted to amplify the MC4R gene and the purified PCR products were sequenced. Alignment of sequence data from each group revealed that there is a variation in MC4R-1 at nucleotide 22 (T-G) (sense mutation) for high egg weight. Hens with the genotype produced significantly (P<0.05) higher egg weight compared to hens with the AA and BB genotypes. There was no significant (P>0.05) effect of this mutation on egg yield. There was no variation detected in MC4R-2. The detected mutation and the analysis of egg production means revealed a significant association between MC4R polymorphism and egg weight. The MC4R-SNP could be considered as a useful marker in chicken selection especially for egg weight