Molecular characterization of the HSP70 and HSP90 genes in Asian clam (Corbicula fluminea) and their expression analysis during heavy metal exposure

Basal mRNA expression of CfHSP70/90 was found in adductor muscle, foot, gill, digestive gland, gonad, and mantle tissues from C. fluminea. The highest expression levels of CfHSP70/90 were observed in the digestive gland. Real-time RT-PCR was used to analyze the mRNA expression of CfHSP70/90 in the digestive gland of C. fluminea exposed to heavy metals Cd2 +, Cu2 +, and Pb2 + for 5, 10, 15, and 20 days. The expression levels of CfHSP70/90 induced by heavy metal gradually, peaked at different times, and then decreased. These results indicate that the CfHSP70/90 genes can be used as sensitive molecular biomarkers of heavy metal pollution in water.