The case for thyroid disruption in early life stage exposures to thiram in zebrafish (Danio rerio).

Abstract

Thiram, a pesticide in the dithiocarbamate chemical family, is widely used to prevent fungal disease in seeds and crops. Its off-site movement to surface waters occurs and may place aquatic organisms at potential harm. Zebrafish embryos were used for investigation of acute (1 h) thiram exposure (0.001-10 µM) at various developmental stages. Survival decreased at 1 µM and 10 µM and hatching was delayed at 0.1 µM and 1 µM. Notochord curvatures were seen at 0.1 and 1 μM thiram when exposure was initiated at 2 and at 10 hpf. Similar notochord curvatures followed exposure to the known TPO inhibitor, methimazole (MMI). Changes were absent in embryos exposed at later stages, i.e., 12 hpf. In embryos exposed to 0.1 or 1 μM at 10 hpf, levels of the thyroid enzyme, Deiodinase 3, increased by 12 hpf. Thyroid peroxide (TPO), important in T4 synthesis, decreased by 48 hpf in embryos exposed to 1 µM at 10 hpf. Thiram toxicity was stage-dependent and early life stage exposure may be responsible for adverse effects seen later. These effects may be due to impacts on the thyroid via regulation of specific thyroid genes including TPO and Deiodinase 3.

Department

Description

Provenance

Citation

Published Version (Please cite this version)

10.1016/j.ygcen.2018.11.003

Publication Info

Chen, Xing, Mingliang Fang, Melissa Chernick, Feng Wang, Jingfeng Yang, Yongli Yu, Na Zheng, Hiroki Teraoka, et al. (2019). The case for thyroid disruption in early life stage exposures to thiram in zebrafish (Danio rerio). General and comparative endocrinology, 271. pp. 73–81. 10.1016/j.ygcen.2018.11.003 Retrieved from https://hdl.handle.net/10161/19205.

This is constructed from limited available data and may be imprecise. To cite this article, please review & use the official citation provided by the journal.

Scholars@Duke

Hinton

David E. Hinton

Nicholas Distinguished Professor Emeritus of Environmental Quality

The Hinton laboratory focuses on mechanistic toxicity in all life stages of small, aquarium model fish and in selected species with particular environmental relevance (freshwater and marine). With the latter, investigations focus on stressor responses and include follow up studies after oil spills. Studies with the laboratory model fish take advantage of the compressed life cycle to improve understanding of organellar, cellular and tissues responses that arise after exposure and follow either a temporal and/or a concentration gradient. At the end of these serial examinations, we have pioneered the use of high resolution light and fluorescent microscopy and electron microscopy in these small fish species to better understand resultant phenotypes and to correlate structural alteration with molecular biological studies. In this way we are anchoring phenotypes with gene expression. In individual fish where specific genes have been mutated (Collaboration with Dr. Keith Cheng, Hershey Medical Center, Hershey, PA) or in individuals exposed to organic substances of known or expected toxicity, structural analysis at various levels of biological organization enables integration across all levels of biological organization enabling whole body phenomics. Special projects include The Duke Superfund Research Center, 2P42-ESO10356-10A2, supported by NIH/NIEHS. Studies investigate responses of fish to polycyclic aromatic hydrocarbons and include early life stages and multigenerational effects. Contaminated and reference sites are included in these investigations of feral fish. Also, we receive funding as part of theme 2 of the Center for Environmental Implications of Nano Technology (CEINT). Our studies seek to determine whether there are specific toxic consequences upon exposure to nano silver (Ag NPs) versus exposure to conventional silver. We hosted Na Zheng (Angie), Visiting Investigator, Associate Professor, Northeast Institute of Geography and Agricultural Ecology, Chinese Academy of Sciences. She was the recipient of a K.C. Wong award supporting her role as visiting investigator. Together, we investigated metals mixtures and embryo toxicity. We collaborate with Stella Marinakos, Pratt School and CEINT on the synthesis and refinement of nanoselenium. This complements work done over the past year with seleno-methionine and sodium selenite in parental and embryo exposures. We continue to investigate ways to assess whole body responses of aquarium model fish and to link phenotype to genotype. Collaboration with the Stapleton laboratory has investigated alterations in embryo and larval zebrafish exposed to flame retardant compounds and selected metabolites. Here our morphologic investigations have helped to differentiate between delayed development and toxicity in the developing eye.


Unless otherwise indicated, scholarly articles published by Duke faculty members are made available here with a CC-BY-NC (Creative Commons Attribution Non-Commercial) license, as enabled by the Duke Open Access Policy. If you wish to use the materials in ways not already permitted under CC-BY-NC, please consult the copyright owner. Other materials are made available here through the author’s grant of a non-exclusive license to make their work openly accessible.