Integration of ATAC-Seq and RNA-Seq Reveals VDR–SELENBP1 Axis Promotes Adipogenesis of Porcine Intramuscular Preadipocytes

Intramuscular fat (IMF) content plays a crucial role in determining pork quality. Recent studies have highlighted transcriptional mechanisms controlling adipogenesis in porcine IMF. However, the changes in chromatin accessibility during adipogenic differentiation are still not well understood. In this study, we performed the assay for transposase-accessible chromatin with high-throughput sequencing (ATAC-seq) and transcriptome sequencing (RNA-Seq) analyses on porcine intramuscular preadipocytes to explore their adipogenic differentiation into mature adipocytes. We identified a total of 56,374 differentially accessible chromatin peaks and 4226 differentially expressed genes at day 0 and day 4 during adipogenic differentiation. A combined analysis of the ATAC-seq and RNA-seq data revealed that 1750 genes exhibited both differential chromatin accessibility and differential RNA expression during this process, including selenium-binding protein 1 (<i>SELENBP1</i>), <i>PLIN1</i>, <i>ADIPOQ</i>, and <i>FASN</i>. Furthermore, we found that vitamin D receptor (VDR) could bind to the promoter region of the <i>SELENBP1</i> gene, activate <i>SELENBP1</i> transcription, and ultimately promote lipid accumulation during adipogenic differentiation. This study provides a detailed overview of chromatin accessibility and gene expression changes during the adipogenic differentiation of porcine intramuscular preadipocytes. Moreover, we propose a novel regulatory mechanism involving the VDR-SELENBP1 signaling axis in adipogenic differentiation.