Trivalent chromium alters gene expression in the mummichog (Fundulus heteroclitus).
Mummichogs (Fundulus heteroclitus) were used as a model fish species to study the effects of trivalent chromium exposure. To ascertain chromium's effects, we examined altered gene expression by differential display between fish exposed in the laboratory and fish collected from a chromium-impacted estuarine site. Twenty differentially expressed genes were found from either laboratory-exposed fish or in fish collected from the field site. Database sequence searches indicated that several of these genes are highly homologous to known sequences, including a fatty acid-binding protein (FABP), cytochrome P4502N2 (CYP2N2), and a precursor to the translation initiation factor eIF2B. Verification of the differentially expressed genes by real-time polymerase chain reaction (PCR) revealed that the fatty acid-binding protein was repressed to a 3.6-times greater extent (3.6-fold) in the field-site animals as compared to a reference site, eIF2B was repressed 2-fold, and an expressed sequence tag (EST) termed A31 was induced 2.6-fold. In the laboratory-exposed animals, A31 was also induced between 2- and 4-fold. However, in contrast to the field-site fish, FABP was upregulated in the chromium-exposed animals. We hope to be able to use A31 as a biomarker for ascertaining the impacts of chromium exposure on fish.
Department of Biological Sciences, University of Texas at El Paso, El Paso, Texas 79968, USA.
Nikki L
NL
Maples
Lisa J
LJ
Bain
D000818:Animals; D002352:Carrier Proteins / Q000378:metabolism; D002857:Chromium / Q000032:analysis / Q000633:toxicity*; D003577:Cytochrome P-450 Enzyme System / Q000378:metabolism; D000072467:Cytochrome P450 Family 2; D017931:DNA Primers; D020717:Eukaryotic Initiation Factor-2B / Q000378:metabolism; D020224:Expressed Sequence Tags / Q000378:metabolism; D050556:Fatty Acid-Binding Proteins; D023781:Fundulidae / Q000378:metabolism*; D005786:Gene Expression Regulation / Q000187:drug effects*; D020133:Reverse Transcriptase Polymerase Chain Reaction; D045483:Rivers / Q000737:chemistry*; D013022:South Carolina; D013054:Spectrophotometry, Atomic; D014874:Water Pollutants, Chemical / Q000032:analysis / Q000633:toxicity*
D002352:Carrier Proteins; D017931:DNA Primers; D020717:Eukaryotic Initiation Factor-2B; D050556:Fatty Acid-Binding Proteins; D014874:Water Pollutants, Chemical; D002857:Chromium; D003577:Cytochrome P-450 Enzyme System; D000072467:Cytochrome P450 Family 2; C404183:cytochrome P-450 CYP2N2 (killifish)