Transcriptomic analysis of the gill and hepatopancreas reveals the thermal adaptation mechanisms of Eriocheir sinensis.

Abstract

Global warming-induced high-temperature stress threatens Eriocheir sinensis aquaculture. This study used transcriptome sequencing combined with histopathological analysis to explore thermal adaptation mechanisms in its gills and hepatopancreas under 38 °C stress. Histopathological results revealed severe tissue damage in the heat-sensitive group (HS). In HS, gills showed distorted and fractured filaments, epithelial detachment, cellular swelling, vacuolation, and nuclear pyknosis, while hepatopancreas exhibited disorganized acinar structures, enlarged intercellular gaps, and extensive nuclear abnormalities. In contrast, heat-tolerant group (HT) displayed milder damage than HS with preserved structural integrity. Transcriptomic analysis identified 869 DEGs in the hepatopancreas and 288 in gills, with 49 shared DEGs enriched in heat shock proteins and antioxidant pathways. Tissue-specific regulation was evident: gills upregulated genes related to ion transport and cell adhesion, while hepatopancreas enhanced fatty acid degradation and detoxification pathways. GSEA further revealed that HT significantly enriched pathways, including protein processing in endoplasmic reticulum, alcoholism in gills, and antigen processing and presentation in hepatopancreas. Key pathways also included MAPK signaling and glutathione metabolism. These findings clarify multi-layered thermal adaptation mechanisms involving tissue-specific transcriptional regulation, synergistic activation of stress-responsive pathways, and structural protection. They provide targets for breeding heat-tolerant strains to mitigate climate change impacts on aquaculture.