Abstract
Intramuscular fat (IMF) serves as a crucial economic indicator of meat quality. To investigate the heterogeneity of IMF composition and its regulatory mechanisms in Xingguo (XG) geese with varying IMF levels, lipidomics and transcriptomics were utilized. The analysis of lipid profiles revealed that the predominant lipids in the IMF of XG geese were glycerophospholipids (GPs), followed by glycerides (GLs). Interestingly, the low-IMF group exhibited an increase in GPs, specifically phosphatidylethanolamines (PEs) and phosphatidylcholines (PCs), while the high-IMF group showed elevated levels of triacylglycerols (TAGs). Transcriptomic analysis indicated that genes related to extracellular matrices (ECM)-receptor interactions, focal adhesion, mitogen-activated protein kinase (MAPK), and forkhead transcription factors O (FoxO) signaling pathways were upregulated in the low-IMF group. In contrast, genes involved in metabolic processes were more pronounced in the high-IMF group. A comprehensive analysis combining lipidomics and transcriptomics identified CD36, fatty acid-binding protein 5 (FABP5), troponin I2 (TNNI2), and coronin-6 isoform X1 (CORO6) as essential regulators influencing IMF accumulation in XG geese. This research emphasizes the significant lipids, genes, and signaling pathways that play roles in IMF accumulation, providing a theoretical basis for enhancing the meat quality of XG geese.