Reduced pigmentation and thyroid hormone disruption in zebrafish embryos caused by industrial sludge near Bohai Bay, China

Wenjing Dong; Xiaoyu Yin; Chelimuge Qi; Tingting Wei; Lijia Wei; Jingfeng Yang; Jingli Mu; Hiroki Teraoka; Wu Dong

Water Biology and Security (Oct 2023)

Reduced pigmentation and thyroid hormone disruption in zebrafish embryos caused by industrial sludge near Bohai Bay, China

Wenjing Dong,
Xiaoyu Yin,
Chelimuge Qi,
Tingting Wei,
Lijia Wei,
Jingfeng Yang,
Jingli Mu,
Hiroki Teraoka,
Wu Dong

Affiliations

Wenjing Dong: College of Animal Science and Technology, Inner Mongolia Minzu University/Inner Mongolia Key Laboratory of Toxicant Monitoring and Toxicology, Tongliao, 028000, China; School of Veterinary Medicine, Rakuno Gakuen University, Ebetsu, 069-8501, Japan
Xiaoyu Yin: College of Animal Science and Technology, Inner Mongolia Minzu University/Inner Mongolia Key Laboratory of Toxicant Monitoring and Toxicology, Tongliao, 028000, China
Chelimuge Qi: College of Animal Science and Technology, Inner Mongolia Minzu University/Inner Mongolia Key Laboratory of Toxicant Monitoring and Toxicology, Tongliao, 028000, China
Tingting Wei: College of Animal Science and Technology, Inner Mongolia Minzu University/Inner Mongolia Key Laboratory of Toxicant Monitoring and Toxicology, Tongliao, 028000, China
Lijia Wei: College of Animal Science and Technology, Inner Mongolia Minzu University/Inner Mongolia Key Laboratory of Toxicant Monitoring and Toxicology, Tongliao, 028000, China
Jingfeng Yang: College of Animal Science and Technology, Inner Mongolia Minzu University/Inner Mongolia Key Laboratory of Toxicant Monitoring and Toxicology, Tongliao, 028000, China
Jingli Mu: College of Geography and Oceanography, Minjiang University, Fuzhou, 350108, China; Corresponding author.
Hiroki Teraoka: School of Veterinary Medicine, Rakuno Gakuen University, Ebetsu, 069-8501, Japan; Corresponding author.
Wu Dong: College of Animal Science and Technology, Inner Mongolia Minzu University/Inner Mongolia Key Laboratory of Toxicant Monitoring and Toxicology, Tongliao, 028000, China; Corresponding author.

Journal volume & issue: Vol. 2, no. 4
p. 100190

Abstract

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In recent years, pollution caused by the discharge of industrial wastewater into Bohai Bay has posed a potential threat to the health of surrounding residents. Sludge was collected from the outlet of a factory that discharges effluent into Bohai Bay, and alcohol extracts of sludge (SE) were prepared. We confirmed by UPLC-MS/MS analysis that the SE contained PAHs, including fluorene, pyrene, and phenanthrene. Zebrafish embryos as animal models were exposed to 0.1, 0.3, 0.5, 1 and 5 mg/mL SE from 2 to 4 h post-fertilization (hpf) until 120 hpf. The results showed that SE caused a concentration-dependent increase in mortality and a decrease in hatchability. We found that SE significantly reduced eye pigmentation and decreased the movement of embryos and larvae. In addition, SE decreased triiodothyronine (T3) content and down-regulated the mRNA expression of some thyroid hormone-related genes including TPO and Thrβ, and caused the up-regulation of Dio2 and Dio3 at 120 hpf. Exposure to three individual PAHs found in SE, namely fluorene, pyrene, and phenanthrene, caused morphological and transcriptional changes that were similar to those caused by SE exposure. These findings indicate that PAHs in SE can reduce the pigmentation of zebrafish, which may be related to the genetic changes associated with thyroid hormones, and that zebrafish eye pigmentation can be used as an indicator of PAHs exposure.

Published in Water Biology and Security

ISSN: 2772-7351 (Online)
Publisher: KeAi Communications Co. Ltd.
Country of publisher: China
LCC subjects: Geography. Anthropology. Recreation: Environmental sciences; Science: Biology (General)
Website: https://www.keaipublishing.com/en/journals/water-biology-and-security/

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