W3 AM Toxicogenomics in Environmental Studies
Wednesday, 16 November 2005: 8:00 AM - 11:40 AM in Ballroom 3

(MOR-1117-842080) Patterns of gene expression using a cDNA Microarray in trout collected from high alpine lakes in Washington State.

Moran, P¹, Aluru, N², Vijayan, M.², ¹ US Geological Survey, Tacoma, WA, USA² University of Waterloo, Waterloo, ON, CAN

ABSTRACT- A growing number of studies have been investigating the use of cDNA libraries and microarray platforms to screen for xenobiotic responses in organisms at the transcriptional level. Fish tissue concentrations of xenobiotic chemicals are often observed at or below levels where other measures of physiological response, ie enzyme biomarkers, can be detected. It is hypothesized that even at very low levels of xenobiotics in fish tissue, the altered expression of certain genes will be indicative of tissue exposure and impact. To this end, liver tissue from rainbow (Oncorhynchus mykiss) and cutthroat (O. clarkii) trout collected from 5 high alpine lakes were analyzed with a targeted rainbow trout cDNA microarray. The 150 genes included on the microarray represent different aspects of teleost physiology; including endocrine, metabolic, immune, and stress-responsive pathways. Multivariate approaches were used to relate measured tissue and sediment concentrations of mercury and organochlorines from these lakes to patterns of gene expression. The variation in gene expression seen across all sites and the use of appropriate standard tissue will be discussed.

Key words: trout, microarray, mercury, organochlorine