Gonadal impairment and parental transfer of tris (2-butoxyethyl) phosphate in zebrafish after long-term exposure to environmentally relevant concentrations

Abstract Tris (2-butoxyethyl) phosphate (TBOEP) is a ubiquitous environmental contaminant due to its overuse. TBOEP has been found to cause reproductive toxicity and endocrine disruption during acute toxic experiment. In this study, we examined the effects of TBOEP on growth in initial generation (F0) zebrafish and transgenerational effects on growth of first generation (F1) larvae after parental long-term exposure (120 d) to environmentally relevant concentrations (0, 0.1, 1, 10 and 100 μg/L). Exposure to TBOEP resulted in significantly less growth as measured by body length, body weight and gonadosomatic index (GSI) in F0 females but not F0 males. Furthermore, the bioaccumulation of TBOEP in gonad, the alteration of the gene transcriptions in the hypothalamic-pituitary-gonadal (HPG) axis, and the delay in gonadal development in both female and male zebrafish were demonstrated. In addition, the residues of TBOEP were detected in F1 larvae after parental exposure, resulting in lower survival and shorter body length, as well as faster heart rate. And no significant changes in gene expressions along the growth hormone/insulin-like growth factor (GH/IGF) axis and the hypothalamic-pituitary-thyroid (HPT) axis were found in F1 larvae. In conclusion, these results indicated that long-term parental exposure to environmentally relevant concentrations of TBOEP could inhibit the development of progeny by parental gonadal impairment and by TBOEP transfer to offspring, instead of gene transcription in GH/IGF and HPT axes.