Integrated lipidomics and transcriptomics to elucidate heterogeneity between intramuscular and abdominal fat and identify serum and liver markers for their differential deposition in chickens.

During broiler production, moderate intramuscular fat (IMF) deposition improves meat quality, whereas excessive abdominal fat (AF) increases production cost. However, reliable molecular markers associated with IMF and AF-specific deposition remain lacking in broiler breeding. To address this, we conducted targeted lipidomic analyses of AF, IMF, serum, and liver, along with transcriptomic analyses of AF and IMF. The results revealed that IMF contained more sphingolipids and fatty acyls, but fewer glycerolipids and sterol lipids than AF. It also had a higher proportion of unsaturated fatty acids. Serum glucose and PS(18:1/22:3) were key molecules for the specific deposition of IMF and AF. HexCer(d18:1/22:0) and PE(16:1/20:1), synthesized in the liver, were directly transported to AF, while Acar(18:0), FFA(20:3), and seven other lipids were transported directly to IMF. PRKAG1 was identified as a regulator of lipid-specific deposition. These findings provide valuable targets for improving meat quality in chickens.