Reproductive toxic effects of chronic exposure to bisphenol A and its analogues in marine medaka (Oryzias melastigma)

• Published in: Aquatic toxicology 2024-06, Vol.271, p.106927-106927, Article 106927
• Main Authors: Chen, Zuchun, Li, Xueyou, Gao, Jiahao, Liu, Yue, Zhang, Ning, Guo, Yusong, Wang, Zhongduo, Dong, Zhongdian
• Format: Article
• Language: English
• Subjects: Bisphenol; Endocrine disruptors; Intergenerational effect; Oryzias melastigma; Reproductive toxicity
• ISSN: 0166-445X; 1879-1514
• DOI: 10.1016/j.aquatox.2024.106927

•Reproductive effects of prolonged bisphenol exposure were evaluated in marine medaka.•Bisphenol exposure resulted in histological damage to the ovary.•Bisphenol exposure altered mRNA expression of genes associated with the HPG axis.•BPAF significantly affected medaka spawning.•Bisphenol exposure had transgenerational effects on medaka. As awareness of BPA's health risks has increased, many countries and regions have implemented strict controls on its use. Consequently, bisphenol analogues like BPF and BPAF are being increasingly used as substitutes. However, these compounds are also becoming increasingly prevalent in the environment due to production, use and disposal processes. The oceans act as a repository for various pollutants, and recent studies have revealed the extensive presence of bisphenols (BPs, including BPA, BPF, BPAF, etc.) in the marine environment, posing numerous health hazards to marine wildlife. Nevertheless, the reproductive toxicity of these chemicals on marine fish is not comprehensively comprehended yet. Thus, the histological features of the gonads and the gene expression profiles of HPG (Hypothalamic-Pituitary-Gonadal) axis-related genes in marine medaka (Oryzias melastigma) were studied after exposure to single and combined BPs for 70 days. The effects of each exposure group on spawning, embryo fertilization, and hatching in marine medaka were also assessed. Furthermore, the impacts of each exposure group on the genes related to methylation in the F2 and F3 generations were consistently investigated. BPs exposure was found to cause follicular atresia, irregular oocytes, and empty follicles in the ovary; but no significant lesions in the testis were observed. The expression of several HPG axis genes, including cyp19b, 17βhsd, 3βhsd, and fshr, resulted in significant changes compared to the control group. The quantity of eggs laid and fertilization rate decreased in all groups treated with BPs, with the BPAF-treated group showing a notable reduction in the number of eggs laid. Additionally, the hatching rate showed a more significant decline in the BPF-treated group. The analysis of methylated genes in the offspring of bisphenol-treated groups revealed significant changes in the expression of genes including amh, dnmt1, dnmt3ab, mbd2, and mecp2, indicating a potential transgenerational impact of bisphenols on phenotype through epigenetic modifications. Overall, the potential detrimental impact of bisphenol on the reproduction of m