John Wiley & Sons, Ltd.

The vas::egfp transgenic zebrafish: A practical model for studies on the molecular mechanisms by which environmental estrogens affect gonadal sex differentiation

0
The vas::egfp transgenic zebrafish (Danio rerio) could significantly enhance studies on the mechanisms by which environmental estrogens disrupt sexual differentiation since the developing gonad can be visualized during early life via fluorescence detection. However, there are methodological challenges regarding dissecting out the gonads in early‐life‐stage fish and transgene responses to estrogen exposure have not been tested. We exposed vas::egfp transgenic zebrafish and their wild‐type siblings to the model estrogen 17α‐ethinylestradiol (EE2) (0.62 and 3.33 ng/L measured concentrations) during sexual development (20 to 60 days post hatch) and used the egfp fluorescence to identify and dissect single gonads (at 40 days post hatch) to provide sufficient RNA for individual gene expression analyses, retaining the remaining gonad in the body cavity for histological analyses of sex and stage of development. Genotyping confirmed that all transgenic control fish were phenotypically egfp‐positive (showed green fluorescence). Interestingly, however, in a few transgenic fish exposed to EE2 there was no phenotypic egfp signal, most notably for the 3.33 ng/L EE2 exposure, and we subsequently found gonadal vasa expression was reduced by this concentration of EE2. Hepatic vitellogenin expression demonstrated that the vas::egfp and wild‐type lines responded to estrogen with an equivalent sensitivity. We conclude that the vas::egfp zebrafish provides an enhanced and practical system for mechanistic studies on the effects of environmentally relevant concentrations of estrogens on gonad development. Environ Toxicol Chem © 2013 SETAC

Customer comments

No comments were found for The vas::egfp transgenic zebrafish: A practical model for studies on the molecular mechanisms by which environmental estrogens affect gonadal sex differentiation. Be the first to comment!