Transcriptome analysis of eyestalk ganglion provides new insights into the immune response of Eriocheir sinensis.

Generally, eyestalk ganglion is regarded as a basic neuroendocrine tissue in decapods. In the past decades, increasing evidence has implied that the nervous system plays important roles in modulating the immune defense against pathogenic microorganisms. However, the molecular mechanisms of nervous system on the innate immunity of decapods remain largely unclear. In this study, we investigated the transcriptomic responses of eyestalk ganglion in Eriocheir sinensis challenged by Vibrio parahaemolyticus. A total of 77 differentially expressed genes (DEGs) were identified, and these DEGs were predicted to be involved in diverse biological pathways including thyroid hormone signaling pathway, peroxisome proliferator-activated receptor (PPAR) signaling pathway, ferroptosis, endocrine system, and neurotrophin signaling pathway. Furthermore, the results indicated that the eyestalk ganglion of E. sinensis could respond to the infection of V. parahaemolyticus by increasing the expression of antibacterial protein such as gillcin and ribosomal protein L27, meanwhile, weakening the inhibition of NF-κB pathway via down-regulating the expression of the suppressor genes such as sterile alpha and TIR motif-containing protein 1 and nicotinic acetylcholine receptor. These findings suggested that V. parahaemolyticus infection triggers the activation of immune response in eyestalk ganglion of E. sinensis, which throws lights on the crucial roles of eyestalk ganglion in crab antibacterial immunity and provides new clues and theoretical basis for disease prevention and control.