Dynamic Transcriptome Profile Analysis of Mechanisms Related to Melanin Deposition in Chicken Muscle Development

The pectoral muscle is an important component of skeletal muscle. The blackness of pectoral muscles can directly affect the economic value of black-boned chickens. Although the genes associated with melanogenesis in mammals and birds have been thoroughly investigated, only little is known about the key genes involved in muscle hyperpigmentation during embryonic development. Here, we analyzed melanin deposition patterns in the pectoral muscle of Yugan black-boned chickens and compared differentially expressed genes (DEGs) between the muscles of Wenchang (non-black-boned chickens) and Yugan black-boned chickens on embryonic days 9, 13, 17, and 21. Melanin pigments were found to gradually accumulate in the muscle fibers over time. Using RNA-seq, there were 40, 97, 169, and 94 genes were identified as DEGs, respectively, between Yugan black-boned chicken muscles and Wenchang chickens at embryonic day 9, 13, 17, and 21 stages (fold change ≥2.0, false discovery rate (FDR) < 0.05). Thirteen DEGs, such as