Effects of the aromatase inhibitor fadrozole on gene expression in the zebrafish brain

Abstract

Aromatase is responsible for the conversion of androgens to estrogens in the brain and gonadal tissues. Teleosts have been characterized as having high levels of brain estrogen biosynthesis. Little is known about the effects of estrogens on brain function in teleosts. The main objective of this study was to assess the effects of fadrozole, a powerful aromatase inhibitor, on gene expression in the zebrafish brain. A fadrozole exposure leads to a decrease in estrogens and an increase in androgens. In the telencephalon, 235 genes were identified by Affymetrix GeneChip analysis as being differentially regulated. Real-time RT-PCR and in situ hybridization were used to validate the data obtained from the microarrays. Collectively, the results provide a better understanding of the effects of aromatase inhibitors on gene expression and also shed light on the underlying effects of sex hormone variation and their importance in the brain of teleosts.