Toxic effects of triphenyltin on the development of zebraflsh (Danio rerio) embryos

Triphenyltin (TPT) is known to be an environmental endocrine disruptor and has adverse effects on aquatic animals. In this study, zebraflsh embryos were treated with three different concentrations (12.5, 25, 50 nmol/L) based on the LC50 value at 96 h post fertilization (96 hpf), after TPT exposure. The developmental phenotype and hatchability were observed and re-corded. Reactive oxygen species (ROS) levels in zebraflsh were detected at 72 hpf and 96 hpf using 2 ',7 '-dichlorodihydrofluorescein diacetate (DCFH-DA) as a probe. The number of neutrophils after exposure was observed using transgenic zebraflsh Tg (lyz: DsRed). RNA-seq analysis was used to compare the gene expression changes in zebraflsh embryos at 96 hpf in the control group and 50 nmol/L TPT exposure group. The data revealed that TPT caused a delay in hatching of zebraflsh embryos in a time-and dose-dependent manner, as well as causing pericardial edema, spinal curva-ture and melanin reduction. ROS levels in embryos exposed to TPT increased, and the number of neutrophils increased after TPT exposure to Tg (lyz: DsRed) in transgenic zebraflsh. RNA-seq results were also analyzed, and KEGG enrichment analysis showed that signiflcant differential genes were enriched in the PPAR signaling pathway (P < 0.05), and the PPAR signaling pathway mainly affected genes related to lipid metabolism. The RNA-seq results were verifled using real-time fluorescence quantitative PCR (RT-qPCR). Oil red O and Nile red staining showed increased lipid accumulation after TPT exposure. These flndings suggest that TPT affects the development of zebraflsh embryos even at relatively low concentrations.