Untargeted metabolomics reveals compositional alterations in the muscle tissue of hybrid crucian carp

Abstract

Fish breeding, including distant hybridization and backcrossing, can reinforce fish growth performance and flesh quality. Using the intercrossing and backcrossing, two improved crucian carps, WR1 and WR2, were generated with a fast growth rate and high-quality flesh. The present study focused on the metabolomic profiles of two genetically improved fish species and investigated the mechanisms of advanced traits underlying metabolic changes by comparing them to their original parents. By comparing WR1 with its parents, 65 differentially expressed metabolites (DEMs) showed significantly higher expression levels in both parental species, whereas 281 DEMs exhibited significantly lower expression levels in both. Among them, LysoPC 18:3, deoxycholic acid, and uric acid were significantly higher, whereas inosine was significantly lower in WR1. In WR2, 75 metabolites were significantly higher in the parents than in WR2, while 413 metabolites were significantly lower in the parents than in WR2. l-Carnitine, creatine, choline, and seven di−/tripeptides were upregulated in WR2. The higher levels of creatine in the muscle of WR2 compared to WR1 and the Weighted Gene Co-expression Network Analysis (WGCNA) results suggest that creatine is the key node that regulates a module containing 72 metabolites. The concentration of creatine in WR2 reached to 28.58 ± 3.01 μmol/g indicating the high concentration of creatine in WR2 was related with its growth performance and high-quality flesh. In conclusion, this study provides the first clues for genetic breeding to reconstruct the metabolic profiles of crucian carp, implying a metabolic mechanism for reinforcing growth performance and flesh quality.