Identification of key hub genes in response to acute hypoxia stress under different chronic salinities of giant freshwater prawn based on WGCNA analysis

The salinity and hypoxia in inland and estuarine waters would cause stress on crustaceans especially the catadromous species. The giant freshwater prawn ( Macrobrachium rosenbergii ) is a typical catadromous species which naturally spawn and hatch in estuarine waters and grow up in inland waters. To elucidate the molecular mechanisms in response to acute hypoxia stress under different chronic salinities, integrated transcriptome and WGCNA analyses were performed on the gill, hepatopancreas, and muscle tissues of M. rosenbergii under acute hypoxia stress under different chronic salinities (0, 6, and 12 ppt). Differentially expressed genes (DEGs) in response to acute hypoxia stress under different chronic salinities were identified in the gill, hepatopancreas and muscle tissues, respectively. Furthermore, a total of 58 hub genes, including ryanodine receptor ( RyR ), enolase-phosphatase E1 ( ENOPH1 ), junctophilin ( JPH ), and thioredoxin-like ( Txl ), were identified from the DEGs. These hub genes were significantly enriched in GO terms of calcium ion transport, muscle structure, and xenobiotic response, and in KEGG pathways including cardiomyopathy, cardiac muscle contraction, taurine metabolism, and the renin-angiotensin system. The RyR and ENOPH1 were further recognized as the key hub genes by co-expression network analysis, which demonstrates a coordinated program centered on calcium signaling and cellular homeostasis in response to acute hypoxia stress under different chronic salinities. The results provide novel insights into the molecular mechanism in response to acute hypoxia stress under different chronic salinities on M. rosenbergii .