Characterization of HSP70 and HSP90 Gene Family in Takifugu fasciatus and Their Expression Profiles on Biotic and Abiotic Stresses Response

Background: Heat shock proteins (HSPs) play crucial roles in response to temperature changes and biotic stresses. However, the HSP gene family in the pufferfish (Takifugu fasciatus) herring has not been comprehensively investigated. Methods and Results: This study presents a systematic analysis of the HSP70 and HSP90 gene families in T. fasciatus, focusing on gene characterization, conserved structural domains, molecular evolutionary history, and expression patterns of the HSP gene family under stress conditions. The findings reveal that 16 HSP genes are evolutionarily conserved, while hspa4 and hsp90aa appear specific to teleost fish. HSP genes exhibit widespread expression across 11 examined tissues, with most demonstrating high expression levels in the heart, brain, and liver. Furthermore, T. fasciatus was subjected to cryogenic and biotic stresses, revealing distinct expression patterns of HSPs under various stress conditions. The response of HSPs to cold stress and Aeromonas hydrophila infection was sustained. In contrast, gene expression of HSPs significantly changed only in the pre-infection period following Ichthyophthirius multifiliis infection, gradually returning to normal levels in the later stages. Conclusions: These experimental results provide a foundation for further in-depth investigations into the characteristics and functions of HSPs in T. fasciatus.