Molecular cloning of the heat shock protein 90 gene in scallop Mizuhopecten yessoensis and the effects of temperature stress on gene expression
Mizuhopecten yessoensis, one of the most highly favored scallops on the international market, has suffered from massive summer mortalities. Water temperature is an important environmental stressor which has significant effects on the physiological and biochemical response of scallops. Heat shock protein 90 (HSP90) plays a key role in defense against various environmental stresses that could damage the cellular and molecular structure of cells. In this study, molecular characterization and expression of HSP90 in M. yessoensis (designated MyHSP90) were analyzed as an indicator to understand the mechanisms of heat shock response in M. yessoensis under temperature stress. The full-length sequence of MyHSP90 cDNA (GenBank accession no. MF196912) is composed of 2639 base pair encoding a 726-amino acid polypeptide with a predicted molecular mass of 83.26 kDa. Tissue expression analysis of MyHSP90 genes revealed ubiquitous expression in each tissue examined, and showed a temperature-dependent response, and the expression level was up-regulated significantly in all the six tissues tested (p < 0.05) except gonad. The results will be useful in furthering the understanding of the massive summer mortalities in M. yessoensis under temperature stress. Additionally, MyHSP90 could be used as a potential biomarker in practice to monitor environmental changes in future studies.