Integrated transcriptomic and metabolic analysis response in gills, hepatopancreas, and muscle metabolism in oriental river prawn Macrobrachium nipponense in response to acute high salinity stress

Salinity is an ecological factor that affects the physiological metabolism, survival, and distribution of crustaceans. Although some crustaceans can tolerate an extensive range of salinity, drastic fluctuations can induce damage and even cause death. The oriental river prawn, Macrobrachium nipponense, is a major commercial aquaculture species in China, Japan, and Southeast Asian countries and can survive in a salinity range of 7–20. To explore the metabolic responses and molecular mechanisms of salinity tolerance in M. nipponense, a liquid chromatography–mass spectrometry-based metabolomic analysis and high-throughput RNA sequencing were combined to evaluate the metabolic effects and primary regulatory pathways in gills, hepatopancreas, and muscle of M. nipponense in response to acute high salinity stress in a time-dependent manner. Differentially expressed genes (DGEs) were identified, and total of 632, 836, and 1246 DEGs with a cutoff of significant two-fold change were differentially expressed in hepatopancreas, gills, and muscle tissues, respectively. The DEGs of hepatopancreas and gill tissues were mainly enriched in PPAR signaling pathway, longevity regulating pathway, protein digestion and absorption, and the DEGs of muscle tissue in arginine biosynthesis, adrenergic signaling in cardiomyocytes, cardiac muscle contraction, and cGMP-PKG signaling pathway. The transcriptomic response suggested that M. nipponense exposed to acute high salinity stress may regulate mechanisms related to ion exchange, metabolism, and immune responses to adapt to the environmental alteration. Through LC-MS analysis, 1432 metabolites (589 negative and 843 positive metabolites) were identified. Metabolomic analysis revealed that multiple amino acids and fatty acids were affected. Integrated transcriptome and metabolome analyses indicated that 16 pathways were identified in three tissues of M. nipponense. In addition, 24 metabolites and 34 related DEGs were recorded. Hence, salinity exposure affected metabolic processes in M. nipponense and a higher expression of aminophospholipid genes and enhanced fatty acids may be related to strengthening tolerance to acute high salinity. Overall, these results provide valuable insights into the mechanisms underlying acute high salinity stress responses and tolerance in M. nipponense