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

(BLA-1117-052413) Copper homeostasis in fish: Is regulation at the transcriptional level?

Blanchard, J¹, Kasper, A¹, Grosell, M, ¹ University of Miami, Miami, FL, USA

ABSTRACT- Copper is an essential nutrient for all organisms yet is potentially toxic. As such, organisms have evolved genes to regulate the uptake, internal transport, cellular trafficking, and excretion of copper. Fish have been demonstrated to regulate copper uptake and excretion when provided with copper above or below their physiological needs. This study aims to examine if regulation of copper uptake and excretion is at the level of gene expression in killifish, Fundulus heteroclitus. Currently, partial sequences of the killifish Cu-ATPase 7A (an exporter), two importers (CTR1 and the divalent metal transporter DMT1), the copper chaperone CCS, and the plasma Cu-carrying protein ceruloplasmin have been obtained. The expression patterns of this set of Cu specific genes are being examined in fish exposed to elevated waterborne copper as well as in copper deficient fish. Copper deficiency will be induced by injections with tetrathiomolybdate. By examining the expression patterns of genes involved in copper homeostasis we hope that a gene expression signature of copper exposure can be established for use in environmental monitoring.

Key words: copper homeostasis, gene expression, Fundulus heteroclitus, quantitative PCR