The use of stress proteins in Mytilus edulis as indicators of chlorinated effluent pollution

This study was performed to examine the use of stress proteins in Mytilus edulis as biomarkers of low level chlorine residual oxidant pollution in the environment. Mussels were exposed to chlorine, heat and heat and chlorine treatments over 14 days. At intervals mussels were removed from each treatment, gill and mantle tissue dissected out and the tissue proteins separated by SDS polyacrylamide gel electrophoresis. The concentration of sample proteins was determined by scanning densitometry and compared to the levels found in control animals. In addition, western blot analysis was performed using monoclonal hsp 70 primary antibody to qualitatively assess stress 70 protein level in each treatment after 14 days. Chlorine residual oxidants in the region of 0.01-0.07 mgl super(-1) induced significant changes in protein expression in the gill of treated mussels. Chlorine treatment was the strongest inducer of 68-72 kDa stress proteins over 14 days and also increased synthesis of 29 kDa protein. Temperature alone increased 43-47 kDa proteins. Each treatment also reduced synthesis of 78 kDa protein (grp 78) and 52-67 kDa proteins. Clear differences were observed in protein syntehsis between gill and mantle tissue. The results indicate that stress proteins can be used as indicators of chlorinated effluent pollution in natural populations.