Effect of exposure to bisphenol A and 17β-estradiol on the sex differentiation in zebrafish (Danio rerio)

The effects of bisphenol A and 17 beta-estradiol on sex differentiation were investigated in the zebrafish, Danio rerio. The 20-day-old fry with undifferentiated gonads were fed with food containing bisphenol A at the dose of 500, 1000,2000 mg center dot kg(-1) and 17 beta-estradiol at the dose of 20 mg.kg(-1) diet for 45 days. Sex ratio and gonadal development after the chemical treatment were determined by histological examination of gonads. In the control group, the sex ratio of fry was 1: 1 (female:male), i.e. 50% of females and 50% of males appeared. The sex of fry fed with 17 beta-estradiol at the dose of 20 mg center dot kg(-1) diet was all females. Feminization of the fry was induced by exogenic 17 beta-estradiol. The sex of fry fed with bisphenol A at the dose of 500, 1000, 2000mg center dot kg(-1) diet was 1.4:1 (p=0.31), 3.8:1 (p=0.01)and 11.5:1 (p<0.01). Bisphenol A induced feminization of the fry at the two highest doses tested.