Proteomic Approach to the Development of Potential Estuarine Biomarkers
The introduction of waste products into rivers and estuaries in industrial and urbanised areas since the industrial revolution has led to significant increases in chemical contamination. As such, it is imperative to develop effective monitoring methods to protect biota and the environment.
Biomarkers provide information on the cause and effect paradigm of contamination by linking contaminants directly to their effects on biota. However, traditional single parameter biomarker analyses can be insensitive, especially at low contaminant levels. Proteomics, the study of proteins, provides a new method for identifying potentially hundreds of species specific biomarkers simultaneously at extremely low levels of contamination and over short time periods, allowing early detection of environmental damage.
Emma Thompson, of Macquarie University, is researching the use of proteomics to assess the effects of metal contamination on Sydney Rock oysters. Saccostrea Glomerata were exposed for four days to three environmentally relevant concentrations (100 µg/l, 50 µg/l and 5 µg/l) of cadmium, copper, lead and zinc. Oyster haemolymph from metal-exposed oysters was compared to haemolymph from non-exposed controls by 2-dimensional electrophoresis to identify differentially expressed proteins. In total 129 proteins (potential biomarkers) were found and we were able to identify a number of these to enable us to see what impact the metals had on the biological functions of oysters. Proteins affecting the cytoskeletal activity of cells and energy metabolism were the most abundant. The data suggest that there are unique protein expression profiles not only for each metal, but at each concentration of metal.
Ongoing work includes testing the efficacy of these potential protein biomarkers in the natural environment using oyster samples from field studies conducted in Lake Macquarie, NSW, Australia.