Profiling and Functional Analysis of mRNAs during Skeletal Muscle Differentiation in Goats

SIMPLE SUMMARY: The growth and development of skeletal muscle is strictly regulated by complex gene networks. In order to explore the genes involved in regulating the differentiation of skeletal muscle satellite cells (MuSCs) in goats, RNA sequencing was used to characterize gene expression profiles during the MuSC differentiation, and to identify differentially expressed genes (DEGs) among the different stages. A total of 2551 DEGs were found. Functional enrichment analysis revealed genes involved in muscle development-related GO terms and pathways, such as muscle structure development, muscle contraction, muscle cell development, muscle cell differentiation, and the MAPK signaling pathway. This study will be useful for future studies on muscle growth and development in goats. ABSTRACT: Skeletal myogenesis is a complicated biological event that involves a succession of tightly controlled gene expressions. In order to identify novel regulators of this process, we performed mRNA-Seq studies of goat skeletal muscle satellite cells (MuSCs) cultured under proliferation (GM) and differentiation (DM1/DM5) conditions. A total of 19,871 goat genes were expressed during these stages, 198 of which represented novel transcripts. Notably, in pairwise comparisons at the different stages, 2551 differentially expressed genes (DEGs) were identified (p < 0.05), including 1560 in GM vs. DM1, 1597 in GM vs. DM5, and 959 in DM1 vs. DM5 DEGs. The time-series expression profile analysis clustered the DEGs into eight gene groups, three of which had significantly upregulated and downregulated patterns (p < 0.05). Functional enrichment analysis showed that DEGs were enriched for essential biological processes such as muscle structure development, muscle contraction, muscle cell development, striated muscle cell differentiation, and myofibril assembly, and were involved in pathways such as the MAPK, Wnt and PPAR signaling pathways. Moreover, the expression of eight DEGs (MYL2, DES, MYOG, FAP, PLK2, ADAM, WWC1, and PRDX1) was validated. These findings offer novel insights into the transcriptional regulation of skeletal myogenesis in goats.