Temporal gene induction patterns in sheepshead minnows exposed to 17beta-estradiol.

Abstract

Gene arrays provide a powerful method to examine changes in gene expression in fish due to chemical exposures in the environment. In this study, we expanded an existing gene array for sheepshead minnows (Cyprinodon variegatus) (SHM) and used it to examine temporal changes in gene expression for male SHM exposed to 100 ng 17beta-estradiol (E(2))/L for five time points between 0 and 48 hr. We found that in addition to the induction of genes involved in oocyte development (vitellogenin [VTG], zona radiata [ZRP]), other genes involved in metabolism and the inflammatory response are also affected. We identified five patterns of temporal induction in genes whose expression was modified due to E(2) exposure. We validated the gene array data for the expression of VTG 1, VTG 2, ZRP 2 and ZRP 3 and found that with low levels of exogenous E(2) (100 ng E(2)/L) exposure, ZRP expression precedes VTG expression. However, at higher concentrations of E(2) (500 ng E(2)/L), the difference in temporal expression appears to be lost. Exposure to high levels of environmental contaminants may affect the normal ordered expression of genes required for reproduction. Gene expression profiling using arrays promises to be a valuable tool in the field of environmental toxicology. As more genes are identified for species used in toxicological testing, researchers will be better able to predict adverse effects to chemical exposures and to understand the relationships between changes in gene expression and changes in phenotype.

• Authors: Iris Knoebl, Jason L Blum, Michael J Hemmer, Nancy D Denslow
• Journal: Journal of experimental zoology. Part A, Comparative experimental biology (J Exp Zool A Comp Exp Biol) Vol. 305 Issue 9 Pg. 707-19 (Sep 01 2006) ISSN: 1548-8969 [Print] United States
• PMID: 16902967 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't, Research Support, U.S. Gov't, Non-P.H.S.)
• Copyright: (c) 2006 Wiley-Liss, Inc.

Chemical References

• Egg Proteins
• Vitellogenins
• zona radiata protein, fish
• Estradiol

Topics

• Animals
• Cyprinidae (genetics, metabolism)
• Egg Proteins (metabolism)
• Estradiol (pharmacology)
• Female
• Gene Expression Profiling
• Gene Expression Regulation (drug effects)
• Liver (metabolism)
• Male
• Nucleic Acid Hybridization (methods)
• Oligonucleotide Array Sequence Analysis
• Transcriptional Activation
• Vitellogenins (genetics, metabolism)