Association of the melanocortin 4 receptor (MC4R) gene polymorphism with growth traits of Hu sheep

In this study, Single Nucleotide Polymorphisms (SNPs) within the full length of the melanocortin 4 receptor (MC4R) gene in Hu sheep were detected and the functional SNPs associated with growth traits of Hu sheep were screened. Using a total of 202 female Hu sheep samples, this study investigated the genetic structure and genetic diversity of the Hu sheep population using PCR amplification, sequencing, and sequence analysis. We analyzed the association between SNPs and body weight and body size traits of Hu sheep and further studied the effect of MC4R gene SNPs on gene transcriptional activity. We found 19 SNPs in the MC4R gene of the Hu sheep population. Furthermore, we observed that the two SNPs (g.706 C -> A, g.732 C -> G) in the MC4R gene were significantly correlated with the adult height of female Hu sheep. The results of dual-luciferase reporter assay showed that the MC4R gene SNPs (g.706 C -> A) had no significant effect on the activity of luciferase (P > 0.05), while the SNPs g.732 C -> G showed significant effect (P < 0.05). The MC4R gene SNP g.732 C -> G could significantly affect the gene transcriptional activity. The g.732 C -> G locus of the MC4R gene can be identified as a candidate functional SNP for the growth traits of Hu sheep.