Expression of the stress-70 protein family (HSP70) due to heavy metal contamination in the slug, Deroceras reticulatum: An approach to monitor sublethal stress conditions

Adult specimens of the slug, Deroceras reticulatum, were exposed to sublethal concentrations of lead, cadmium, and zinc. After three weeks of exposure, atomic absorption spectrophotometry revealed accumulation of all these metals in the animals. Highest exposure concentrations of lead, cadmium, and zinc resulted in highest contents of the respective metals in the slugs. In accordance with this effect, D. reticulatum showed an increased expression of the 70 kD stress protein (stress-70, hsp70) in response to exposure to all three heavy metals tested. Quantification of hsp70 increase took place with standardized Western-blotting and densitometric imaging after background correction. Multiple investigations revealed different reaction patterns to lead, cadmium, or zinc exposure and showed that the applied technique serves as a versatile tool to assess invertebrate stress reactions in response to environmentally relevant toxicants.