This study investigated the cellular and transcriptional mechanisms underlying lipid deposition in highly marbled pork using Laiwu pigs with high (HLW) or low (LLW) intramuscular fat (IMF) contents. Single-nucleus RNA sequencing (snRNA-seq) and bulk RNA sequencing revealed that HLW pigs had a higher percentage of adipocytes and altered expression of genes involved in lipid metabolism and fatty acid elongation. Three adipocyte subpopulations were identified, with DGAT2+/SCD+ and FABP5+/SIAH1+ cells predominantly found in HLW pigs. Fibro/adipogenic progenitors (FAPs) were shown to differentiate into IMF cells, contributing to a significant portion of adipocytes. These findings provide insights into the cellular and molecular mechanisms of marbling formation.
