Research Article: Impact of ۱۷-α-Ethinylestradiol on immune function and reproductive gene expression in Zebrafish (Danio rerio): implications for aquaculture of important commercial fish species

In the present study, we detected changes in immune parameters, antioxidant enzymes, and reproductive gene expression in adult female zebrafish (Danio rerio) exposed to different concentrations of ۱۷-ethinylestradiol (EE۲). A total of ۳۰۰ healthy adult females were divided into ۱۵ aquaria, which were allocated to five treatments with three replicates. The zebrafish were exposed to varying concentrations of EE۲ including ۰.۵ (T۰.۵), ۵ (T۵), ۵۰ (T۵۰), and ۵۰۰ (T۵۰۰) ng L⁻¹, along with an unexposed control group (ultrapure water, T۰) for ۲۱ days. After ۲۱ days, lysozyme activity, total immunoglobulin, superoxide dismutase, malondialdehyde (MDA), alkaline phosphatase (ALP), alanine aminotransferase, aspartate aminotransferase (AST) and reproductive gene expression were evaluated.  The results showed that exposure to EE۲ caused a significant decrease in lysozyme activity, and total immunoglobulin levels, but had no significant effect (p>۰.۰۵) on the SOD activity. The MDA level was significantly higher in the high-dose hormone treatments than in the control group (p<۰.۰۵). Different EE۲ concentrations had a significant impact on ALP and ALT activities and they increased in fish exposed to EE۲ compared to the control (p<۰.۰۵). The expression levels of gnrh۲, gnrh۳, gnrhr۲, gnrhr۳, lhβ, and fshβ genes significantly increased (p < ۰.۰۵) in the females. In contrast, the expression of the hsd۳b gene significantly decreased (p>۰.۰۵). Significant decreases (p<۰.۰۵) were also observed in the expression of lhcgr and fshr genes in the female zebrafish. In conclusion, our results demonstrate that different concentrations of EE۲ can disrupt steroidogenesis by interfering with the expression of genes related to sex steroid levels in the female broodstock of zebrafish.

کلیدواژه ها:

Zebrafish ، Endocrine disrupter ، ۱۷-α-ethinylestradiol ، Genes expression