Abstract
BACKGROUND: Intramuscular fat (IMF) is a key determinant of meat quality enhancement in pigs. However, its correlation with subcutaneous fat (SCF) deposition presents a challenge. The precise regulation of IMF lipogenesis, without impacting SCF deposition, is a critical issue in the pig industry. To investigate this, our study examined the lipid profiles of longissimus dorsi (LD) muscle and subcutaneous adipose tissue in high IMF (IMFH) and low IMF (IMFL) Chinese Erhualian pigs using lipidomics techniques. RESULTS: We identified 112 differentially abundant lipids (DALs) in the muscle and 101 DALs in the adipose tissue. Notably, 105 specific DALs associated with IMF, including various candidate markers like upregulated lipids of PS (19:2/18:1), TG (14:2/4:0/4:0), PS (17:1/18:2), FA(10:0) + COOH:(s), CL (20:4/18:2/18:2/18:2), and downregulated lipids of FA (20:4), SM (d43:5), TG (38:1/22:6), PC (22:3/20:3), and PC (18:2/24:8), were identified. These specific DALs were implicated in the regulation of linoleic, arachidonic, and alpha-linolenic acid metabolism, and choline metabolism in cancer. We further discovered that the lysophosphlipase 1 (LYPLA1) gene promotes differentiation and lipid deposition of intramuscular pre-adipocytes by affecting the phosphatidylcholine (PC) content. CONCLUSIONS: Our findings identify specific lipids associated with IMF accumulation in both skeletal muscle and subcutaneous adipose depots, thereby offering valuable insights into the lipid composition of porcine IMF and new avenues for targeted IMF deposition.