The lack of knowledge regarding how the genome is regulated during skeletal myogenesis in pigs hinders the identification of genetic variants for meat traits. Here, we systematically characterized the cis-regulatory elements (CREs, including promoters, enhancers, and others) by using Hi-C coupled chromatin cleavage and tagmentation (HiCuT, H3K27ac), assay for transposase-accessible chromatin using sequencing (ATAC-seq), and RNA-seq to analyze primary myoblasts and in vitro well-differentiated myotubes, and generated an atlas of promoter-enhancer interactions (PEIs) during myogenic differentiation. In total, 179,895 and 159,255 loops were identified in myoblasts and myotubes, respectively, which could be grouped into 3 categories: the interactions between promoter and enhancer (P–E), between promoter and promoter (P–P), and between other genomic regions (O–O). Furthermore, 22,645 cis-expression quantitative trait loci (eQTLs) were pinpointed by integrating public genome-wide association studies (GWAS) and eQTL datasets. Notably, novel promoter-like enhancers were verified, and cis-eQTLs in promoter-like enhancers might influence gene expression over long ranges. In addition, 39,069 structural variants (SVs) within the CREs were identified. A transcription factor (TF)-promoter/enhancer regulatory network for myogenesis was generated, revealing several novel TFs relevant to myogenic differentiation. This work provides a valuable resource for understanding genomic regulation in pig muscles and filtering potential variants to develop breeds with desirable traits.

pig  /  promoter–enhancer interaction  /  cis-eQTLs  /  meat traits  /  myogenic differentiation