Gene expression patterns - a tool for bioanalysis

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 17 beta-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 efl alpha. A significant increase in the expression of vig1 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.