The effects of a dietary selenium exposure on molecular signalling cascades in juvenile rainbow trout
University of New Brunswick
Selenium is an essential trace element that is a by-product of mining activities. Se exposure has been observed to have adverse effects on fish. The objectives of this study were to determine the effects of dietary Se on growth, energy stores and molecular signaling pathways in juvenile rainbow trout. Fish were fed different nominal doses of Se (control, 5, 10, 20 or 40 mg/kg Se dry weight) over 60 days. Fish fed the 20 and 40 mg/kg Se dose had reduced fork length, bodyweight and lower hepatic triglyceride levels compared to control fish. Microarray analysis revealed that pathways involved in triglyceride utilization were upregulated, suggesting that there may be a compensatory molecular response in the liver to decreased triglycerides. Reduced growth can be detrimental to juvenile fish that are at a sensitive life stage and this may result in adverse effects in fish populations at Se-contaminated sites in the environment.