HA5 Genomics and Proteomics
Room 17A/B, Level 4
8:00 AM - 12:00 PM, Thursday, 13 November 2003
Chair: Ferguson, Lee ,
(517) Microarray analysis in largemouth bass and fathead minnows.
Larkin, P1, Carter, B1, Kroll, K2, Liu, L2, Sahni, A2, Farmerie, W2, Denslow, N2, 1 EcoArray LLC, Alachua, FL, USA2 Biotechnology Program, University of Florida, Gainesville, FL, USA
ABSTRACT- Microarrays provide genetic fingerprints of exposure to specific environmental contaminants, information that may prove useful for risk assessment of polluted sites. While microarrays are readily available for humans, rats, and rodents, to date microarrays have not been available for many non-mammalian species that are commonly used for risk assessment, including fish. This is, in large part, due to the paucity of sequence information available for these animals. In this study, mRNA sequences were obtained for both largemouth bass (Micropterus salmoides) and fathead minnows (Pimephales promelas) by a variety of methods including sequencing genes from cDNA libraries, subtraction libraries, and direct cloning of genes. Clones were sequenced in a high throughput format and assembled and clustered to eliminate redundant genes. BLAST sequence homology searches were run in batch mode for gene identification. Unique genes were also annotated using the GO database. Approximately 550 unique largemouth bass genes and 850 unique fathead minnow genes were obtained. These genes encode proteins that are involved in multiple pathways (steroidogenesis, reproduction, cellular signaling, hemostasis). We have used largemouth bass microarrays to identify gene expression fingerprints for fish exposed to estradiol, nonylphenol and DDE. While the three compounds are similar in eliciting an estrogenic response in bass, upregulating genes involved in oogenesis, they produce expression fingerprints that distinguish them from one another. This suggests that expression fingerprints may provide an inexpensive and accurate method to identify environmental contaminants and their biochemical mechanisms of action.
Key words: fish, microarray, endocrine disruption, genomics