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

Area of Science:

• Environmental Toxicology
• Molecular Biology
• Fish Biology

Background:

• Gene arrays are effective tools for assessing environmental chemical impacts on fish gene expression.
• Sheepshead minnows (Cyprinodon variegatus) are a relevant model organism for toxicological studies.

Purpose of the Study:

• To investigate temporal changes in gene expression in male sheepshead minnows exposed to 17beta-estradiol (E(2)).
• To identify gene expression patterns and validate array data under varying E(2) concentrations.

Main Methods:

• Expanded sheepshead minnow gene array utilized for expression profiling.
• Exposure of male fish to 100 ng/L E(2) over five time points (0-48 hours).
• Validation of key gene expression data (VTG, ZRP) using quantitative methods.

Main Results:

• E(2) exposure induced genes related to oocyte development (vitellogenin [VTG], zona radiata [ZRP]), metabolism, and inflammation.
• Five distinct temporal gene induction patterns were identified.
• At low E(2) levels, ZRP expression preceded VTG expression; this temporal difference diminished at higher E(2) concentrations.

Conclusions:

• Environmental contaminants like E(2) can disrupt the ordered gene expression critical for fish reproduction.
• Gene expression profiling offers a valuable approach for predicting adverse effects of chemical exposures.
• Further gene identification will enhance understanding of gene expression-phenotype relationships in toxicological assessments.