Custom microarray construction and analysis for determining potential biomarkers of subchronic androgen exposure in the Eastern Mosquitofish (Gambusia holbrooki)

BMC Genomics
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Abstract

Background

The eastern mosquitofish (Gambusia holbrooki) has the potential to become a bioindicator organism of endocrine disrupting chemicals (EDCs) due to its androgen-driven secondary sexual characteristics. However, the lack of molecular information on Gholbrooki hinders its use as a bioindicator coupled with biomarker data. While traditional gene-by-gene approaches provide insight for biomarker development, a holistic analysis would provide more rapid and expansive determination of potential biomarkers. The objective of this study was to develop and utilize a mosquitofish microarray to determine potential biomarkers of subchronic androgen exposure. To achieve this objective, two specific aims were developed: 1) Sequence a Gholbrooki cDNA library, and 2) Use microarray analysis to determine genes that are differentially regulated by subchronic androgen exposure in hepatic tissues of 17β-trenbolone (TB) exposed adult female Gholbrooki.

Results

A normalized library of multiple organs of male and female Gholbrooki was prepared and sequenced by the Illumina GA IIx and Roche 454 XLR70. Over 30,000 genes with e-value ≤ 10-4were annotated and 14,758 of these genes were selected for inclusion on the microarray. Hepatic microarray analysis of adult female Gholbrooki exposed to the vehicle control or 1 μg/L of TB (a potent anabolic androgen) revealed 229 genes upregulated and 279 downregulated by TB (one-way ANOVA, p < 0.05, FDR α = 0.05, fold change > 1.5 and < −1.5). Fifteen gene ontology biological processes were enriched by TB exposure (Fisher’s Exact Test, p < 0.05). The expression levels of17β-hydroxysteroid dehydrogenase 3 and zona pellucida glycoprotein 2 were validated by quantitative polymerase chain reaction (qPCR) (Student’s t-test, p < 0.05).

Conclusions

Coupling microarray data with phenotypic changes driven by androgen exposure in mosquitofish is key for developing this organism into a bioindicator for EDCs. Future studies using this array will enhance knowledge of the biology and toxicological response of this species. This work provides a foundation of molecular knowledge and tools that can be used to delve further into understanding the biology of Gholbrooki and how this organism can be used as a bioindicator organism for endocrine disrupting pollutants in the environment.

Additional publication details

Publication type Article
Publication Subtype Journal Article
Title Custom microarray construction and analysis for determining potential biomarkers of subchronic androgen exposure in the Eastern Mosquitofish (Gambusia holbrooki)
Series title BMC Genomics
DOI 10.1186/1471-2164-14-660
Volume 14
Issue 660
Year Published 2013
Language English
Publisher BioMed Central
Contributing office(s) Southeast Ecological Science Center
Description art660: 11 p.
Online Only (Y/N) N
Additional Online Files (Y/N) N