|
2C - Biomarkers (TUP/90) Metallothionein as a biomarker in the New Zealand common bully. Laurie, Andrew1, 1 Landcare Research, Lincoln, Canterbury, New Zealand ABSTRACT- The use of indicator species that represent local fauna is a valuable way to derive reliable information on the effects of contaminants. We chose the common bully (Gobiomorphus cotidianus), a small freshwater fish indigenous to New Zealand, as a model indicator species since it is widespread in rivers and streams, and is quite sensitive to environmental perturbations. Initially the bully was used as an indicator for heavy metal pollution by targeting the metallothionein (MT) gene as a biomarker. Expression of hepatic MT was measured using quantitative fluorogenic (RT)-PCR to measure MT mRNA, which was normalised against 18S RNA levels. Concentration-response experiments were performed to demonstrate induction of MT at elevated levels of water-borne copper, zinc, and cadmium. The analysis was extended to the field by measuring MT levels in bullies from a variety of pristine and polluted habitats to correlate metal concentrations with MT levels. The natural variation of MT expression was evaluated to determine whether this affects our ability to discern MT increases in response to elevated levels of heavy metals. Initial results suggest that hepatic MT in the common bully will be a sensitive and reliable indicator of metal contamination in streams. Key words: metallothionein, biomarker, aquatic, fish |
