Gene expression patterns – a tool for bioanalysis

Abstract

Gene expression patterns are efficient tools to elucidate responses to hormones as well as endocrine disruptors at the molecular level. Male zebrafish (Danio rerio) were exposed to 17β-estradiol (E2). Transcriptome analysis was first carried out by quantitative polymerase chain reaction (PCR) of the gene coding for vitellogenin (vtg1) in relation to the housekeeping gene ef1α. A significant increase in the expression of vtg1 was found at concentrations >100 ng L⁻¹ E2. Then DNA microarray experiments were performed to examine the expression levels of the zebrafish genome. A total of 210 sequences were regulated in male zebrafish exposed to 500 ng L⁻¹ E2. They include genes involved in the estrogen pathway, such as the gene coding for the estrogen receptor, and in embryonic development, such as homeo box genes. A complete list of up- and down-regulated genes and sequences is provided in this article.

Keywords:

• Gene expression
• Estrogen
• Zebrafish

Acknowledgement

We are indebted to the EU for supporting the EDEN project (Endocrine disrupters: Exploring Novel Endpoints, Exposure, Low-Dose and Mixture-Effects in Humans, Aquatic Wildlife and Laboratory Animals). Furthermore we would like to thank the Lehrstuhl fuer Tierhygiene at the TU Munich for inviting us to use the LightCycler.