Integrating transcriptome and metabolome reveals sex-dependent meat quality regulation in Qiandongnan Xiaoxiang chickens

This study integrated metabolomics and transcriptomics to elucidate molecular mechanisms regulating meat quality in Qiandongnan Xiaoxiang chickens across sexes and muscle types. Male chickens exhibited significantly higher shear force in breast and leg muscles (P < 0.01) and lower cooking loss in leg muscle (P < 0.05) compared to females. Metabolomic profiling identified 24 sex-differential metabolites, enriched in amino acid and nicotinate metabolism pathways. Transcriptomic analysis revealed 377 and 486 differentially expressed genes (DEGs) in breast and leg muscles between sexes, respectively, associated with steroid biosynthesis and energy metabolism. Integrative analysis highlighted histidine metabolism (characterized by anserine accumulation in females via MAOA upregulation) and nicotinate metabolism as key sex-specific pathways. Tissue comparisons demonstrated distinct regulation of linoleic acid metabolism, purine metabolism, and oxidative phosphorylation. These findings provide novel insights into molecular networks underlying meat quality differences and identify potential biomarkers for enhancing nutritional value in poultry breeding.