COI Funded Project: New Approaches to Detecting Developmental Toxicity in Estuarine Fishes

John Stegeman, Biology

Project Duration: 6/1/99-12/31/00
Key Words: chemical contaminants, effects on Fundulus, environmental toxicology, P450 genes

Proposed Research

Assessing the effects of contaminants in coastal ecosystems remains a difficult task. With the inevitable human population growth over the next decades, the need to reliably and simply assess potential threats to coastal systems may become even more important. This proposal takes advantage of recent discoveries and combines these with recently available technologies, to develop and test new biotechnological approaches for detecting effects of chemicals on coastal fishes. Our proposed studies are based on the putative involvement of certain genes and proteins as indicators of exposure and mediators of toxic effects of chemicals, particularly aromatic and chlorinated hydrocarbons such as PCBs. The studies will focus on a fish species that is important in coastal marshes and estuaries, Fundulus heteroclitus. Fundulus heteroclitus is used increasingly in environmental toxicology studies.

The project would involve collection of fish from marshes, and analysis of molecular changes associate with contamination in embryos as well as in adults. The assays will involve a newly acquired method for quantitative measurement of the increase in gene expression that should allow us to examine very small samples, such as one or a few eggs of fish, or a small amount of blood. We will obtain eggs from the females, and fertilize these in the laboratory, and measure the expression of selected P450 genes and also of a gene for a potential target gene (vascular endothelial growth factor) in the resulting embryos. We also will collect blood and measuring P450 gene expression in blood cells (lymphocytes). Both types of tissue would be assayed by a molecular biological procedure that specifically amplifies the signal from a given gene. The studies could establish a new approach to the problem for assessing exposure of coastal fish to toxic chemicals. The proposed studies will engage the efforts of students from different departments at WHOI (Biology) and MIT (Electrical Engineering and Toxicology).