Transcriptome and histopathology analysis of the gills of Eriocheir sinensis provide novel insights into the molecular mechanism of Pb stress

The Chinese mitten crab (Eriocheir sinensis) is an important aquatic economic species in China, and also a representative model crustacean to study the impact of environmental pollutants in water. As a common contaminant and heavy metal, lead (Pb) easily causes potentially irreversible toxic effects on aquatic organisms. Although increasing attention has been paid to the effect of heavy metals on E. sinensis, the molecular mechanism responding to Pb exposure in E. sinensis has not been comprehensively studied. Therefore, based on histopathology and transcriptome, this study attempted to explore the molecular mechanism of exposure to Pb in gill tissues. Histological analysis showed that the gills were damaged under the Pb stress, affecting their biological functions. Additionally, transcriptome data identified 2,505 differentially expressed genes (DEGs), some of which were related to osmotic regulation, energy metabolism, immune defense, and apoptosis, playing vital roles in response to Pb stress. Our study revealed the molecular mechanism of E. sinensis responding to Pb exposure, providing an important foundation for understanding the harmfulness of Pb toxicity to E. sinensis during aquaculture.