The effect of diazinon as agricultural pesticides on reproductive indices and related genes expression in zebrafish ( Danio rerio )

Abstract

This study aimed to investigate the effects of sub-lethal concentrations of diazinon on the expression of genes involved in spermatogenesis (activin, androgen receptor and FSH receptor) and sex hormones in the male zebrafish (Danio rerio). For this purpose, 360 male zebrafish aged about 2.5 months were exposed to diazinon for one month with sub-lethal concentrations (5, 10 and 20% LC50) and control groups (3 replications). At the end of the period, RNA was sampled and extracted from gonadal tissue. Real-time PCR analysed gene expression, and sex hormones were tested using an ELISA kit. The results of genes expression related to steroidogenesis showed a significant difference between different treatments for FSH receptor gene (p < 0.05). FSH receptor gene expression had a decreasing pattern with increasing diazinon toxin concentration. Moreover, there was a significant difference in the expression levels of the activin gene between different treatments (p < 0.05). The expression level of the activin gene had a decreasing pattern with an increasing concentration of diazinon toxin. The endogenous receptor gene showed a significant decreasing pattern with a rising concentration of diazinon toxin. Moreover, the serum hormone measurements showed a significant decreasing pattern with increasing concentration of diazinon toxin (p < 0.05), although the levels of estradiol had an increasing pattern with a growing concentration of diazinon. In general, it can be concluded that exposure to diazinon toxin could disrupt the reproduction efficiency in zebrafish.