Identification of key genes and metabolites involved in intramuscular fat deposition in Laiwu pigs through combined transcriptomic and lipidomic analyses.

Pork quality is a key goal in commercial pig farming. Intramuscular fat (IMF) content in pigs serves as a critical determinant of meat quality, yet its regulatory mechanism remains unclear. In this study, two different pig breeds Chinese native breed Laiwu (fatty-type) and Yorkshire (lean-type), were selected as research subjects. The molecular regulatory mechanisms affecting IMF content were investigated through integrated transcriptomic and lipidomic analysis. We identified critical genes, including ACC1, FASN, ELOVL6, SCD, and DGAT2, and elucidated their synergistic interactions in promoting IMF deposition in Laiwu pigs. The findings reveal that the coordinated action of genes such as ACC1 and FASN promotes the increased production of palmitic acid, which was subsequently elongated and desaturated by ELOVL6 and SCD to form long-chain fatty acids necessary for TG synthesis. Additionally, DGAT2 facilitates the extensive synthesis of TG, which is stored in lipid droplets under the regulation of PLIN1. This increased triglyceride synthesis and storage capacities in Laiwu pigs, functioning as one of the key factors contributing to its high IMF content. The study highlights the importance of gene-lipid interactions in IMF deposition and offers novel insights into the genetic and molecular basis of IMF accumulation, particularly in fatty pig breeds like the Laiwu. Our research findings provide new directions for developing targeted genetic or nutritional interventions to enhance IMF content and improve meat quality.