In silico analysis of Hsp70 genes in Ctenopharyngodon idella and their expression profiles in response to environmental stresses

Heat shock protein 70 (Hsp70) is a crucial member of the Hsp family, which is present in many animals, and acts as a chaperone to protect the organism from damage caused by various environmental stresses, particularly unfavorable temperatures. In this study, we used homologous gene search and domain analysis to identify sixteen Hsp70 genes (named as CiHSP genes) from the genome of grass carp (Ctenopharyngodon idella). These genes were classified into ten subfamilies based on their conserved structures and phylogenetic analysis. To investigate the biological functions of CiHSP genes in grass carp, we analyzed public RNA-Seq data, and found that most members of the CiHSP gene family were highly expressed in the brain and kidney, suggesting potential roles in protecting brain cells and participating in fish immunological processes. Additionally, these CiHSP genes were characterized as responding to high density and high temperature stress, with most members significantly upregulated under high temperature conditions. These findings demonstrate the critical roles of CiHSP genes in grass carp development and their response to environmental stress, which will provide valuable insights for determining their function and potential application in fish production in the future.