Combined Untargeted LC−MS Metabolomics and Lipidome Reveal the Key Metabolites and Genes of Meat Quality Regulation and Their Regulatory Mechanisms in Chinese Pigs

Chinese indigenous pig breeds are favored by consumers due to their superior meat quality and higher intramuscular fat (IMF) content compared with those of commercial crossbred pigs. However, the molecular mechanism underlying IMF deposition is poorly understood. In this study, we performed integrated metabolomic and lipidomic analyses on longissimus dorsi muscles from three representative breeds, Shengxian Spotted Pig (SXS), Jiaxing Black Pig (JXB), and Qinglian Black Pig (QLB), to identify metabolites and genes associated with IMF accumulation, constructed differential metabolite profiling, and performed lipid profiling between the three breeds. Pathway enrichment analysis revealed significant alterations in the amino acid metabolism, glycerophospholipid metabolism, and fatty acid biosynthesis pathways. Integrative analysis highlighted IMP3 as a key regulator associated with IMF deposition. Functional validation indicated that IMP3 promotes muscle differentiation and modulates amino acid and fatty acid metabolic pathways. These findings elucidate the molecular basis of lipid deposition in local Chinese pig breeds and provide potential targets for the genetic improvement of meat quality.