Cadmium bioaccumulation and metallothionein induction in the liver of the Antarctic teleost Trematomus bernacchii during an on-site short-term exposure to the metal via seawater

Abstract

A short-term experiment (7 days) was carried out to study cadmium accumulation and metallothionein (MT) gene expression in the liver of the Antarctic teleost Trematomus bernacchii when exposed to 2.0 mg Cd L−1 seawater. Metal determinations were carried out by differential pulse anodic stripping voltammetry while MT gene expression was determined by the Real Time PCR Detection System. In controls, the Cd concentration and the MT gene expression remained practically constant during the experiment (8.8 ± 0.9 µg g−1 d.w. and 1.0 ± 0.2 mRNA a.u., respectively). In exposed organisms, while Cd increased almost linearly with time, up to 30 ± 2 µg g−1 d.w., i.e. by a factor of ∼3.5 in 7 days, MT gene expression, after a little delay, increased almost exponentially up to a value of 86 ± 25 mRNA a.u. after 7 days, by a factor of ∼90. These results confirm the potential usefulness utility of T. bernacchii as a bioindicator of environmental pollution in Antarctica.