Phosphatidic acid acts as a signaling lipid to direct glycerolipid versus glycerophospholipid flux in chicken muscle.

Chicken is the fastest-growing animal protein source globally. However, long-term directional selection has created significant quality differences between fast-growing broilers and indigenous breeds, with the latter exhibiting superior lipid composition and flavor, though the underlying metabolic mechanisms remain unclear. This study integrated lipidomics, metabolomics, and transcriptomics to systematically characterize lipid deposition in breast muscle of fast-growing Arbor Acres broilers versus indigenous Gushi chickens, identifying the 3-phosphoglycerate (3-PGA)/glycerol-3-phosphate (G3P)/phosphatidic acid (PA) axis as a core metabolic node. Functional validation revealed PA acts as a key signaling lipid, regulating breed-specific lipid composition through PLPP1 (glycerolipid pathway) and CDS2 (glycerophospholipid pathway). In ovo PA supplementation at embryonic day 17 activated PPAR signaling and promoted lipid droplet formation and triglyceride deposition without affecting growth performance. These findings establish PA-mediated metabolic partitioning as a molecular switch for breed-specific lipid composition, providing novel insights into meat quality regulation and molecular targets for breeding superior chicken.