A positive correlation between mercury and oxidative stress-related gene expression (GPX3 and GSTM3) is measured in female Double-crested Cormorant blood.
Mercury (Hg) is a widespread contaminant that has been shown to induce a wide range of adverse health effects in birds including reproductive, physiological and neurological impairments. Here we explored the relationship between blood total Hg concentrations ([THg]) and oxidative stress gene induction in the aquatic piscivorous Double-crested Cormorants (Phalacrocorax auritus) using a non-lethal technique, i.e., blood gene expression analysis. P. auritus blood was sampled at five sites across the Great Lakes basin, Ontario, Canada and was analyzed for [THg]. To assess cellular stress, the expression of glutathione peroxidases 1 and 3 (GPX1, GPX3), superoxide dismutase 1 (SOD1), heat-shock protein 70 kd-8 (HSP70-8) and glutathione S-transferase µ3 (GSTM3) were measured in whole blood samples using real-time RT-PCR. Results showed a significantly positive correlation between female blood [THg] and both GPX3 and GSTM3 expression. Different levels of oxidative stress experienced by males and females during the breeding season may be influencing the differential oxidative stress responses to blood [THg] observed in this study. Overall, these results suggest that Hg may lead to oxidative stress as some of the cellular stress-related genes were altered in the blood of female P. auritus and that blood gene expression analysis is a successful approach to assess bird health condition.
School of Environmental Studies, Queen's University, Kingston, ON, K7L 3N6, Canada.
Laura A
LA
Gibson
Raphael A
RA
Lavoie
Sonja
S
Bissegger
Linda M
LM
Campbell
Valerie S
VS
Langlois
D000818:Animals; D001717:Birds / Q000097:blood / Q000235:genetics* / Q000502:physiology; D004784:Environmental Monitoring; D004785:Environmental Pollutants / Q000032:analysis* / Q000633:toxicity; D005260:Female; D005786:Gene Expression Regulation / Q000187:drug effects*; D005979:Glutathione Peroxidase / Q000235:genetics* / Q000378:metabolism / Q000502:physiology; D005982:Glutathione Transferase / Q000235:genetics* / Q000378:metabolism / Q000502:physiology; D016014:Linear Models; D008297:Male; D008628:Mercury / Q000032:analysis* / Q000633:toxicity; D018384:Oxidative Stress / Q000235:genetics*
D004785:Environmental Pollutants; D005979:Glutathione Peroxidase; D005982:Glutathione Transferase; D008628:Mercury