Non-lethal heat shock enhances the immune response of Procambarus clarkii hemocytes to Vibrio parahaemolyticus through the HSP90 gene family.

This research focuses on Procambarus clarkii and systematically explores the mechanism of action of the HSP90 gene family when responding to non-lethal heat shock (NLHS) and Vibrio parahaemolyticus infection. We have identified four members of the HSP90 gene family. The characteristics of the proteins encoded by these genes are significantly different, which implies functional divergence. Multiple sequence alignment and phylogenetic analysis suggested that the structure of HSP90 proteins exhibits both conservatism and diversity, indicating functional divergence among family members. The genes are unevenly distributed across chromosomes and there are no tandem repeat genes. HSP90 genes are differentially expressed in tissues, with high expression in hemocytes indicating immune involvement. After NLHS, the expression of some genes increased dramatically and reached the peak after injection with V. parahaemolyticus. However, for some other genes, their expression did not change significantly, indicating that they may be involved in different types of regulation. Protein interaction and co-expression analyses revealed HSP90 proteins interact with innate immune proteins and collaborate with TLR pathway members. DsRNA silencing of HSP90 downregulates key TLR molecules (TLR2, TRAF6, IRAK4, MyD88) at different time points, confirming their functional immune association. This indicates HSP90 genes play a key role in anti-pathogen mechanisms. The study provides molecular markers for breeding stress-resistant P. clarkii and theoretical support for crustacean stress biology research.