Sequencing of the metallothionein gene using the RT-PCR (reverse transcriptase polymerase chain reaction) method in the Antarctic fish Pagothenia borchgrevinki to determine the exposure of Antarctic fish to heavy metals

The development and application of a new molecular approach for quantifying the exposure of Antarctic fish to heavy metals was tested. The approach uses quantitative RT-PCR (reverse transcriptase polymerase chain reaction) to measure the extent of induction of the metallothionein gene which is sensitive to the presence of environmental metals such as cadmium and copper. The Antarctic fish species Pagothenia borchgrevinki was sampled from the relatively polluted Winterquarters Bay (McMurdo Station) and the relatively pristine Backdoor Bay (Cape Royds). The fish were weighed, measured and sexed and samples were taken of various tissues and organs for histopathology (liver, gills, gonads), RNA extraction (liver) and metal analysis (liver). Blood samples were also taken. The metallothionein gene was sequenced and run through the RT-PCR process and the results were compared between sites.