Effect of insecticide Diazinon on expression of steroidogenic genes and DNA methylation of promoter site of StAR gene during in vitro maturation of goat oocyte

This research was conducted to investigate the effect of different concentrations of Diazinon as a pesticide, that is widely used in agriculture, on the expression of steroidogenic genes and DNA methylation of promoter site of StAR gene in in vitro maturation of goat oocytes. To prepare goat oocytes, ovaries were prepared from a slaughterhouse and transported to the laboratory into the flask containing warm saline (30-34oC). Oocyte-cumulus complexes (COC) was removed from small antral follicles with the slicing method, and transferred to Medium 199. COCs were placed in a maturation medium for 24 hours, and were reached to metaphase stage Π (nuclear maturation). The experiment was examined in a completely randomized design with five treatments included: control, 75, 37.5, and 18.75 μM of Diazinon, and 0.5 μM of DMSO. The results showed that the addition of different concentrations of Diazinon in the goat maturation medium, significantly decreased the maturation rate (P <0.05) compared to the control treatment, and also it led to a decline in the gene expression of CYP11A1, 17βHSD, CYP19 in cumulus cells. However, the expression of StAR gene was increased. Therefore, it can be concluded that Diazinon has a disruptor effect on oocyte maturation rate, and expression of steroidogenic genes in cumulus cells.