A comprehensive analysis based on histopathology, metabolomics and transcriptomics reveals molecular regulatory mechanisms of the red claw crayfish (Cherax quadricarinatus) in …

The maintenance of homeostasis is central for the survival of organisms under exposure to various types of stress, toxicants, and pathogens, and small metabolites often play key roles in this process. Vibrio parahaemolyticus is one of the main pathogens causing acute hepatopancreatic necrosis disease in crustaceans. Here, we characterized changes in the histopathology of the hepatopancreas, gene expression, and the metabolism of small molecules in Cherax quadreicarinatus challenged with V. parahaemolyticus. Susceptible crayfish were characterized by hem-orrhage in the hepatopancreatic interstitium, irregular contraction of the stellate structures in the lumen, the partial loss of luminal structures, and increased vacuolization; asymptomatic crayfish exhibited a small amount of hemorrhage, partial contraction of the stellate structures, and no significant increase in the number of vac-uoles. V. parahaemolyticus challenge also resulted in significant differences in the accumulation of metabolites such as adenosine triphosphate, adenosine diphosphate, inosine triphosphate, glycodeoxycholic acid (hydrate), phosphatidylcholine, deoxyguanosine, arginine, and adenosine. Transcriptome analysis revealed a total of 3678 differentially expressed genes that were mainly enriched in the following Kyoto Encyclopedia of Genes and Genomes pathways: phagosome, starch and sucrose metabolism, apoptosis, cysteine and methionine metabolism, Vibrio cholerae infection, oxidative phosphorylation, Toll and IMD signaling pathways, arginine biosynthesis, and other signaling pathways. A comprehensive analysis showed that Lysosomal, citric acid cycle (TCA cycle), vitamin digestion and absorption, bile secretion, glycolysis/gluconeogenesis, oxidative phosphorylation, tryp-tophan metabolism, pyrimidine metabolism, purine metabolism, pyruvate metabolism, ascorbate and aldehyde metabolism, NOD-like receptor signaling pathway, AMPK signaling pathway, PI3K-Akt signaling pathway, cAMP signaling pathway, calcium signaling pathway, and other signaling pathways were also significantly enriched under V. parahaemolyticus challenge. Our results indicate that C. quadricarinatus maintains its homeostasis under challenge with V. parahaemolyticus by activating multiple signaling pathways that mediate the repair of hep-atopancreatic damage.