Dietary Methionine Affect Meat Qulity and Myostatin Gene Exon 1 Region Methylation in Skeletal Muscle Tissues of Broilers

Dietary amino acids imbalance will result in stunted broiler performance and deteriorated meat quality, which are involved in various biochemical cycles in vivo. In this study, the effects of dietary methionine on meat quality and methylation of myostatin exon 1 were investigated. Drip loss of the broilers fed with diet of high methionine levels (0.2%) increased from (6.3 ± 0.1)% (control group) to (10.1 ± 1.0)%, and the muscle shearing force increased from (22.8 ± 1.9) N (control group) to (26.3 ± 2.3) N. Moreover, many CpG sites were found at the myostatin exon 1 region (nucleotides 2 360-2 540 bp). To further understand the regulation of broiler myostatin expression, the methylation status of broiler myostatin exon 1 and its mRNA expression were analyzed. At the myostatin exon 1 region where CG enriches (nucleotides 2 360-2 540 bp), the percentages of methylation were 46 and 84% in low Met and high Met content groups after 55-d feeding, respectively. In skeletal muscle tissues, the exon 1 hypermethylation status of myostatin gene was found to be negatively correlated with the gene expression. These results suggested that methylation of this gene is a dynamic process, which plays a dominant role in regulating gene expression for development of individuals.