Quantitative prediction of zebrafish reproductive impairment via androgen receptor-driven adverse outcome pathway

Summary

Exogenous androgenic contaminants have long been of concern and are associated with reproductive impairment in fish. Although Toxcast has screened a large number of compounds using in vitro testing, it is challenging to conduct high-throughput tests for complex effects in vivo and to assess apical endpoints such as reproduction further quantitatively. Therefore, we developed a quantitative prediction method for reproductive dysfunction in zebrafish based on the adverse outcome pathway (AOP) framework. We carried out in vitro androgen activity tests for 16 compounds and a 21-day exposure experiment of androgen receptor (AR) agonism reference chemical 17β-trenbolone (TB) in zebrafish. The results revealed that TB mainly affected the levels of 11-ketotestosterone, estradiol, and vitellogenin in females by mediating AR, and caused abnormal ovarian development and fecundity decline. Then, AOP leading to reproductive dysfunction in female zebrafish (ZqAOP) was assembled and quantified, and it was validated to determine the potential and reliability for chemical extrapolation. Finally, the ZqAOP model was applied for predicting the potential reproductive impairments of eight compounds in environmental concentrations and global surface water samples with AR activity. This study provides a new insight into screening and assessing large numbers of chemicals with potential endocrine-disrupting effects.