Environmentally Relevant Concentrations of Tris(1,3-dichloro-2-propyl) Phosphate Induced a Female-Biased Osteotoxicity in Crucian Carp (Carassius auratus)

Abstract

Tris­(1,3-dichloro-2-propyl) phosphate (TDCIPP) has been frequently detected in the aquatic environments and aquatic organisms, and several studies have reported that great concentrations of TDCIPP could cause malformation in zebrafish (Danio rerio) embryo/larvae. However, the chronic effects of environmentally relevant concentrations of TDCIPP on bone phenotype remain unclear. In this study, 1-month-old crucian carp (Carassius auratus) were exposed to 0, 500, or 5000 ng/L TDCIPP for 18 months, and the effects on skeletal malformation were evaluated. The results demonstrated that exposure to 5000 ng/L TDCIPP significantly increased malformation rate in female fish compared with the control, and no such malformation effect was observed in males. Furthermore, histopathological results showed a reduction of bone thickness and bone separation and vertebrae compression in deformed females of the 5000 ng/L TDCIPP exposure group. Transcriptomic sequencing was performed to evaluate the effects of TDCIPP on gene expression. It was found that TDCIPP significantly changed the expressions of genes involved in complement and coagulation cascades pathway, p53 signaling pathway, ribosome biogenesis in eukaryotes, and steroid hormone biosynthesis, which might be responsible for the observed caudal malformation in this study. These results provided a novel knowledge of osteotoxicity of TDCIPP.