|
(W/EH119) HSP60 response in soil nematode Plectus acuminatus: suitable biomarker for toxic stress in field bioassays? Arts, Marie-José1, Kammenga, Jan1, 1 ABSTRACT- Biomarkers are tools for the risk assessment of chemicals in biosystems. They can bridge the gap between chemical analyses and impairment of physiology of organisms leading towards effects at the ecosystem level. Within the EU-funded BIOPRINT-II project suitable biomarkers have been selected in a number of soil invertebrates representing various trophic levels on the basis of laboratory experiments. For the bacterivorous nematode Plectus acuminatus the heat shock protein 60 (HSP60) response proved to be a promising biomarker for chemical stress at a sublethal level. Heat shock proteins (HSPs) are stress proteins, molecular chaperones that mediate the correct assembly of other polypeptides and whose concentration can greatly increase due to stress. To evaluate the potential and limitations of the HSP60 response with respect to other biomarkers under field conditions, a field experiment was performed in Avonmouth, West England. Six sample sites were selected along a gradient of zinc (100-25000 ppm), lead (20-15000 ppm), copper (10-2500 ppm) and cadmium (1-200 ppm). P. acuminatus was transplanted to these sites in minicontainers, thus exposed in an in situ bioassay. After 5 days of exposure, the nematodes were extracted from the minicontainers. Subsequently, the proteins were extracted from these nematodes and subjected to one-dimensional SDS-PAGE and subsequent Western blotting. HSP60 antibodies were applied as well as tropomyosin antibodies, the latter serving as an internal standard. Grey values of the blot bands were measured by densitometric image analysis. The results are presented and the suitability of the HSP60 response in P. acuminatus as a biomarker for toxic stress in field bioassays is discussed. Key words: hsp60, nematode, in situ bioassay, metal polluted soil |
