Jump to main content or area navigation.

Contact Us

Extramural Research

2006 Progress Report: Systems Biology Modeling of Fathead Minnow Response to Endocrine Disruptors

EPA Grant Number: R831848
Title: Systems Biology Modeling of Fathead Minnow Response to Endocrine Disruptors
Investigators: Denslow, Nancy , Orlando, Edward F. , Sepúlveda, Maria (Marisol) S. , Watanabe, Karen
Institution: University of Florida , Florida Atlantic University - Boca Raton , Oregon Health & Sciences University , Purdue University - Main Campus
EPA Project Officer: Saint, Chris
Project Period: August 1, 2004 through July 31, 2007
Project Period Covered by this Report: August 1, 2005 through July 31, 2006
Project Amount: $722,851
RFA: Computational Toxicology and Endocrine Disruptors: Use of Systems Biology in Hazard Identification and Risk Assessment (2004)
Research Category: Economics and Decision Sciences , Computational Toxicology , Endocrine Disruptors , Health Effects

Description:

Objective:

The objective of this study is to develop molecular and protein biomarkers that are diagnostic for endocrine disruption. To be diagnostic, these biomarkers must report on biochemical pathways that are adversely affected by endocrine disrupting compounds and correlate with physiological changes and reproductive endpoints. We are developing a computational model that we will use to evaluate the biomarkers. This model takes into account the pharmacodynamics and kinetic parameters of the compounds as well as the physiological endpoints adversely affected by the exposures. We have three specific aims: (1) determine and compare gene and protein expression profiles and physiological and reproductive endpoints for adult fathead minnows (FHM) exposed to a model estrogen ethynylestradiol (EE2), androgen (17β-trenbolone), or their antagonists (ZM 189,154 and flutamide, respectively); (2) predict gene expression patterns for zearalenone, an environmental estrogen; and (3) develop a computational modeling framework that integrates exposure concentration, gene expression and proteomic profiles with physiological endpoints. We hypothesize that genomic and proteomic approaches will provide a global understanding of mechanisms of action that will relate specifically to reproductive endpoints.

Progress Summary:

We have completed gene expression fingerprints for the estrogen/antiestrogen set. While the exposures to the androgen/antiandrogen set are complete, we have just ordered a new FHM-44K array that has recently become commercially available. This array will offer us the best way to evaluate genome-wide changes in gene expression over the original 2K array.

For the estrogen/antiestrogen set, we observed the expected gene expression changes in males. For example, we saw an increase in hepatic vitellogenin (Vtg) as well as other proteins involved in the synthesis and export of proteins from the liver to the blood. In the gonad, we saw a down regulation of genes involved in sperm biosynthesis, which explains the feminization and decreased spermatogenic activity of male fish exposed to estrogens reported by others. In the brain, we found fewer genes whose expression changed, but we did see the expected increase in brain aromatase. We are still in the process of analyzing these results.

We also have performed a 21-day EE2 exposure study with both males and females and found that only the highest dose of EE2 (50 ng/L, static replacement) caused obvious reproductive dysfunction, such as feminization of males and increased clutch size in females. These results are consistent with what has been reported with other fish species; however we will repeat this experiment using a flow-through system to ensure that fish are exposed to the nominal chemical concentrations throughout the experiment.

This year we simplified our FHM physiological model structure to include tissue compartments for gill, brain, gonad, and liver, with all remaining tissues combined in a compartment named “other.” The outputs from this model include concentrations of steroid hormones (E2, T, and for males only 11-KT), luteinizing hormone (LH) and vitellogenin (VTG). We are currently calibrating it with data from Dr. Gerald Ankley’s laboratory (U.S. Environmental Protection Agency Mid-Continent Ecology Division) for control (unexposed) female FHM. Because of the tremendous variability in FHM, we are using a probabilistic parameter estimation method, Markov Chain Monte Carlo simulation, to obtain distributions of input parameters that will characterize a population of unexposed FHM.

The investigators participated in a number of small fish meetings with collaborators from EPA, including:

  • Fourth Society of Environmental Toxicology and Chemistry World Congress and 25th Annual Meeting, Portland, OR, November 14-18, 2004.
  • Society of Environmental Toxicology and Chemistry North America 26th Annual Meeting, Baltimore, MD, November 13-17, 2005.
  • Small fish meeting, Duluth, MN, March 2005.
  • Small fish meeting, Athens, GA, May 2006.
  • Society of Environmental Toxicology and Chemistry North America 27th Annual Meeting, Montreal, QC, Canada, November 5-9, 2006.

Future Activities:

The investigators plan to: (1) complete microarray experiments and couple these to physiological endpoints, and (2) complete a physiologically based mathematical model for the hypothalamus-pituitary-gonadal (HPG) axis.


Journal Articles on this Report : 6 Displayed | Download in RIS Format

Other project views: All 23 publications 7 publications in selected types All 6 journal articles

Type Citation Project Document Sources
Journal Article Hemming JM, Allen HJ, Thuesen KA, Turner PK, Waller WT, Lazorchak JM, Lattier D, Chow M, Denslow N, Venables B. Temporal and spatial variability in the estrogenicity of a municipal wastewater effluent. Ecotoxicology and Environmental Safety 2004;57(3):303-310.
abstract available   full text available
R831848 (2006)
  • Abstract from PubMed
  • Full-text: ScienceDirect-Full Text HTML
    Exit
  • Abstract: ScienceDirect-Abstract
    Exit
  • Other: ScienceDirect-Full Text PDF
    Exit
  • Journal Article Knoebl I, Hemmer MJ, Denslow ND. Induction of zona radiata and vitellogenin genes in estradiol and nonylphenol exposed male sheepshead minnows (Cyprinodon variegatus). Marine Environmental Research 2004;58(2-5):547-551.
    abstract available   full text available
    R831848 (2006)
  • Abstract from PubMed
  • Full-text: ScienceDirect - Full Text HTML
    Exit
  • Abstract: ScienceDirect-Abstract
    Exit
  • Other: ScienceDirect - Full Text PDF
    Exit
  • Journal Article Knoebl I, Blum JL, Hemmer MJ, Denslow ND. Temporal gene induction patterns in sheepshead minnows exposed to 17β-estradiol. Journal of Experimental Zoology Part A: Ecological Genetics and Physiology 2006;305A(9):707-719.
    abstract available   full text available
    R831848 (2006)
  • Abstract from PubMed
  • Full-text: ResearchGate-Abstract & Full Text PDF
    Exit
  • Abstract: Wiley-Abstract
    Exit
  • Journal Article Villeneuve DL, Larkin P, Knoebl I, Miracle AL, Kahl MD, Jensen KM, Makynen EA, Durhan EJ, Carter BJ, Denslow ND, Ankley GT. A graphical systems model to facilitate hypothesis-driven ecotoxicogenomics research on the teleost brain-pituitary-gonadal axis. Environmental Science & Technology 2007;41(1):321-330.
    abstract available   full text available
    R831848 (2006)
  • Abstract from PubMed
  • Full-text: ResearchGate-Abstract & Full Text PDF
    Exit
  • Abstract: ES&T-Abstract
    Exit
  • Journal Article Villeneuve DL, Knoebl I, Larkin P, Miracle AL, Carter BJ, Denslow ND, Ankley GT. Altered gene expression in the brain and liver of female fathead minnows Pimephales promelas Rafinesque exposed to fadrozole. Journal of Fish Biology 2008;72(9):2281-2340.
    abstract available   full text available
    R831848 (2006)
  • Full-text: University of Nebraska-Lincoln-Full Text PDF
    Exit
  • Abstract: Wiley - Abstract
    Exit
  • Journal Article Watanabe KH, Jensen KM, Orlando EF, Ankley GT. What is normal? A characterization of the values and variability in reproductive endpoints of the fathead minnow, Pimephales promelas. Comparative Biochemistry and Physiology C: Toxicology & Pharmacology 2007;146(3):348-356.
    abstract available   full text available
    R831848 (2006)
  • Abstract from PubMed
  • Full-text: ScienceDirect - Full Text HTML
    Exit
  • Abstract: ScienceDirect-Abstract
    Exit
  • Other: ScienceDirect - Full Text PDF
    Exit
  • Supplemental Keywords:

    microarrays, reproductive effects, computational model, Pimephales promelas, HPG axis, risk assessment, EDCs,, RFA, Health, Scientific Discipline, POLLUTANTS/TOXICS, Health Risk Assessment, Chemicals, Endocrine Disruptors - Environmental Exposure & Risk, endocrine disruptors, Risk Assessments, Biochemistry, Biology, Endocrine Disruptors - Human Health, bioindicator, assays, biomarkers, fish, EDCs, endocrine disrupting chemicals, exposure studies, animal model, sexual development, mechanistic screening, animal models, human growth and development, toxicity, endocrine disrupting chemcials, fathead minnow, estrogen response, invertebrates, invertebrate model, hormone production, androgen, estrogen receptors, ecological risk assessment model, assessment technology, estuarine crustaceans

    Progress and Final Reports:
    Original Abstract
    2005 Progress Report

    Top of Page

    The perspectives, information and conclusions conveyed in research project abstracts, progress reports, final reports, journal abstracts and journal publications convey the viewpoints of the principal investigator and may not represent the views and policies of ORD and EPA. Conclusions drawn by the principal investigators have not been reviewed by the Agency.

    Jump to main content.