Looking for estrogen mimics using transgenic tg(cyp19a1b-GFP) zebrafish embryos

The tg(cyp19a1b-GFP) transgenic zebrafish expresses GFP under the control of the cyp19a1b gene, encoding brain aromatase. This gene has two major characteristics : it is only expressed in radial glial progenitors in the brain of fish and it is exquisitely sensitive to estrogens. Based on these properties, we demonstrate that natural or synthetic hormones (alone or in binary mixture), including androgens or progestagens, and industrial chemicals induce a concentration-dependent GFP expression in radial glial progenitors. As GFP expression can be quantified by in vivo imaging, this model represents a very powerful tool to screen and characterize compounds potentially acting as estrogens mimics either directly or after metabolization by the zebrafish embryo. This study also shows that radial glial cells that act as stem cells are direct targets for a large panel of endocrine disruptors, calling to more attention regarding the impact of environmental estrogens and/or certain pharmaceuticals on brain development. Altogether these data identify this in vivo bioassay as an interesting alternative to detect estrogen mimics in hazard and risk assessment perspective