ZFIN ID: ZDB-PUB-180831-2
Tris(1,3-dichloro-2-propyl) phosphate Exposure During Early-Blastula Alters the Normal Trajectory of Zebrafish Embryogenesis
Dasgupta, S., Cheng, V., Vliet, S.M.F., Mitchell, C.A., Volz, D.C.
Tris(1,3-dichloro-2-propyl) phosphate (TDCIPP) is an organophosphate flame retardant used around the world. Within zebrafish, we previously showed that initiation of TDCIPP exposure during cleavage (0.75 h post-fertilization, hpf) results in epiboly disruption at 6 hpf, leading to dorsalized embryos by 24 hpf - a phenotype that mimics the effects of dorsomorphin (DMP), a bone morphogenetic protein (BMP) antagonist that dorsalizes embryos in the absence of epiboly defects. The objective of this study was to 1) investigate the role of BMP signaling in TDCIPP-induced toxicity during early embryogenesis; 2) identify other pathways and processes targeted by TDCIPP; and 3) characterize downstream impacts of early developmental defects. Using zebrafish as a model, we first identified a sensitive window for TDCIPP-induced effects following exposure initiation at 0.75 hpf. We then investigated the effects of TDCIPP on the transcriptome during the first 24 h of development using mRNA- and amplicon-sequencing. Finally, we relied on whole-mount immunohistochemistry, dye-based labeling, and morphological assessments to study abnormalities later in embryonic development. Overall, our data suggest that initiation of TDCIPP exposure during early-blastula alters the normal trajectory of early embryogenesis by inducing gastrulation defects and aberrant germ layer formation, leading to abnormal tissue and organ development within the embryo.