HSP60 as a potential biomarker of toxic stress in the nematode plectus acuminatus

The induction of heat shock proteins (HSPs) in the nematode Plectus acuminatus (Nematoda; Plectidae) was studied following exposure to heat, copper, and cadmium. Mini two-dimensional polyacrylamide gel electrophoresis was used for protein separation and poly- and monoclonal antibodies raised against specific HSPs in various organisms were used to detect specific HSPs. Both HSP60 and HSP70 could be identified after exposure of nematodes to heat stress, indicating the broad crossreactivity among species to the antibodies used. The monoclonal antibody LK-2 was selected for further investigation with the HSP60 response to heavy metals. The induction of HSP60 was related to increased concentrations of cadmium and copper. For copper, the induction of HSP60 was three orders of magnitude more sensitive than was the EC20 for reproduction. For cadmium, HSP60 induction was one order of magnitude more sensitive. The results point out that HSP60 induction occurred at concentration levels that are realistic for the field situation. It is therefore suggested that HSP60 may be suitable as a potential biomarker to toxicant stress in P. acuminatus.