Integrated metabolome and transcriptome provide insights on meat quality differences between Fujian yellow and New Zealand white rabbits

Rabbit meat is recognized for its nutritional benefits and affordability. However, research into the primary factors influencing its flavor, especially among various rabbit breeds, remains insufficient. This study conducted a comprehensive comparison of meat quality, metabolomic, and transcriptomic profiles between the longissimus dorsi muscles of Fujian yellow rabbits (FJY) and New Zealand white rabbits (NZW), which exhibit significant variations in body size and growth rate. A total of 68 samples, with 34 from each breed, were analyzed. Results indicated that FJY rabbits had lower body weights but higher dressing percentages than NZW rabbits. FJY meat was higher brightness (L*) and yellowness (b*), lower redness (a*), along with significantly reduced cooking losses. In terms of proximate composition, FJY meat exhibited higher protein and collagen levels but significantly less fat and moisture than NZW meat. Additionally, FJY meat contained higher levels of myristic acid, palmitoleic acid, cis-11-eicosapentaenoic acid, α-linolenic acid, and a higher MUFA/FA ratio. Metabolomic analysis using HPLC-MS/MS identified 231 differential metabolites, including amino acids and their derivatives, organic acids, and heterocyclic compounds. Transcriptomic analysis via RNA-seq revealed 211 differentially expressed genes potentially involved in meat quality regulation. Integrated analyses identified 70 KEGG pathways associated with pivotal genes, such as CPT2, PAK1, SLC7A7, and TAS1R2 , which exhibited correlations with differential metabolites like cholesterol, benzoic acid, putrescine, and N-acetylcysteine, suggesting a synergistic effect on meat quality. Overall, these findings provide valuable insights into the distinct meat quality characteristics that underpin the improved quality and flavor of rabbit meat.