Data_Sheet_7_Genome-Wide Analysis of H3K27me3 in Porcine Embryonic Muscle Development.XLSX

The trimethylation of histone H3 lysine 27 (H3K27me3) is one of the most important chromatin modifications, which is generally presented as a repressive mark in various biological processes. However, the dynamic and global-scale distribution of H3K27me3 during porcine embryonic muscle development remains unclear. Here, our study provided a comprehensive genome-wide view of H3K27me3 and analyzed the matching transcriptome in the skeletal muscles on days 33, 65, and 90 post-coitus from Duroc fetuses. Transcriptome analysis identified 4,124 differentially expressed genes (DEGs) and revealed the key transcriptional properties in three stages. We found that the global H3K27me3 levels continually increased during embryonic development, and the H3K27me3 level was negatively correlated with gene expression. The loss of H3K27me3 in the promoter was associated with the transcriptional activation of 856 DEGs in various processes, including skeletal muscle development, calcium signaling, and multiple metabolic pathways. We also identified for the first time that H3K27me3 could enrich in the promoter of genes, such as DES, MYL1, TNNC1, and KLF5, to negatively regulate gene expression in porcine satellite cells (PSCs). The loss of H3K27me3 could promote muscle cell differentiation. Taken together, this study provided the first genome-wide landscape of H3K27me3 in porcine embryonic muscle development. It revealed the complex and broad function of H3K27me3 in the regulation of embryonic muscle development from skeletal muscle morphogenesis to myofiber maturation.

组蛋白H3赖氨酸27三甲基化（histone H3 lysine 27, H3K27me3）是最为关键的染色质修饰之一，在多种生物学过程中通常作为抑制性表观遗传标记。然而，猪胚胎肌肉发育过程中H3K27me3的动态全局分布特征仍未明确。本研究以杜洛克胎儿交配后33、65、90天的骨骼肌为实验材料，绘制了全基因组范围内H3K27me3的综合表观图谱，并同步分析了对应的转录组数据。转录组分析共鉴定出4124个差异表达基因（differentially expressed genes, DEGs），揭示了三个发育阶段的核心转录调控特征。研究发现，胚胎发育过程中全局H3K27me3水平持续升高，且H3K27me3修饰水平与基因表达呈显著负相关。启动子区域的H3K27me3缺失与856个差异表达基因的转录激活密切相关，这些基因涉及骨骼肌发育、钙信号通路及多种代谢通路等多个生物学过程。本研究还首次证实，H3K27me3可富集于DES、MYL1、TNNC1及KLF5等基因的启动子区域，在猪卫星细胞（porcine satellite cells, PSCs）中负向调控基因表达；H3K27me3的缺失可显著促进肌细胞分化。综上，本研究首次绘制了猪胚胎肌肉发育过程中H3K27me3的全基因组表观图谱，揭示了H3K27me3在调控胚胎肌肉发育（从骨骼肌形态发生到肌纤维成熟）过程中的复杂且广泛的调控功能。