Fig. 6. Effects of cadmium (Cd) exposure on expression of cytoplasmic (HSP70, HSP90) and mitochondrial (HSP60) heat shock proteins in gill and hepatopancreas (HP) cells of oysters. HSP levels were measured using immunoblotting and expressed as % of the respective controls. Cells were exposed to varying Cd levels (x-axis) for 4 h at 20°C. Vertical bars represent s.e.m. Asterisks denote values significantly different from the respective controls (P<0.05). N=5.