Cd accumulation and Cd-metallothionein as a biomarker in Cepaea hortensis (Helicidae, Pulmonata) from laboratory exposure and metal-polluted habitats.

Cepaea hortensis is a widespread terrestrial pulmonate, contributing significantly to element fluxes in soil ecosystems. Due to its capacity of accumulating certain trace elements in its tissues, Cepaea hortensis can serve as a biological indicator of metal accumulation in contaminated areas. In response to Cd exposure this species and related helicid pulmonates are also able to synthesize an inducible, Cd-binding metallothionein (MT) isoform specifically serving in binding and detoxification of this metal.

Isoform-specific quantification of metallothionein in the terrestrial gastropod Helix pomatia. II. A differential biomarker approach under laboratory and field conditions.

The two function-specific metallothionein (MT) isoforms characterized from the midgut gland and mantle tissue of Helix pomatia differ substantially in their metal-binding preferences, as well as molecular and biochemical features. These differences make them potential candidates for biomarker studies based on a differential, isoform-specific approach. To prove this hypothesis, induction experiments with two metals (Cd and Cu) that are normally bound by the two isoforms were compared with a range of organic chemicals and physical stressors under laboratory conditions to test the responsiveness of the two isoforms to the stressors applied.