Effect Of BDE-209 On In Vitro Maturation And Parthenogenetic Development Of KB Mouse Oocytes

ObjectivesThe present study was carried out to investigate the effect of BDE-209 on the rate of germinal vesicle breakdown,the releasing rate of the first polar body and the survival rate of the in vitro maturation oocytes from the mice.After the parthenogenetic activation process of the mature oocytes,the influence on embryonic development of the BDE-209 was investigated.MethodsThe oocytes were acquired from the sexual maturation and no pregnant mice after superovulation.The oocytes were cultivated in the BDE-209 of DMEM(low sugar) medium.Three experiment Groups B,C,D were treated with BDE-209 at dosages of 10μg/mL,20μg/mL,40μg/mL,respectively.The control group A was treated with BDE-209 at dosage of 0μg/mL.The releasing rate of the first polar body(PB1) and the survival rate of oocytes were observed at 8h and 16h after the BDE-209 treatment. The rate difference between the experiment groups and the control group was calculated.The premature oocytes were obtained from mice ovarianstimulated by PMSG..The rate of germinal vesicle breakdown was observed after a 12-h treatment with BDE-209.The rate of the first polar body was recorded after a 24-h treatment with BDE-209,and the MⅡoocytes were treated with parthenogenetic activation.The rate of parthenogenetic activation was calculated and compared within each groups. After the parthenogenetic activation,the oocytes were cultivated in CZB medium which contains various concentrations of BDE-209.The 2-cell rate was observed after the 24-h culture and the 4-cell rate was observed after the 48-h culture,the formation rates of the 2-cell and the 4-cell were recorded and compared within each groups.ResultsThere was no significant difference observed in the releasing rates of the first polar body beween the groups received an 8-h BDE-209 treatment and the 16-h treatment(P＞0.05).No statistical significance was obtained in the rate of the first polar body between four groups in 8 hours and 16 hours(P＞0.05).There was a significant decrease in the survival rates of oocytes after the groups received a 16-h treatment with BDE-209 compared to the groups received an 8-h BDE-209 treatment (P＜0.05).In vitro culture of the premature oocytes,there was no statistical significance in the rates of the germinal vesicle breakdown within each experiment group with respect to the control groups following an 12-h treated with BDE-209(P＞0.05).There was significantly decreased in the rate of the first polar body of the premature oocytes after 24 hours culture(P＜0.05).There were no significant difference in the rates of parthenogenetic activation after the mature oocytes activated by ethanol(P＞0.05).There were significant decreases in the both rates of the 2-cell and 4-cell formation after the embryo cultivated in BDE-209 medium for 24 hours and 48 hours compared to the control groups.ConclusionsThe results indicated that BDE-209 did not inhibit the release of the first polar body but lower the survival rate of the oocytes in vitro culture.The BDE-209 significantly reduced the releasing rate of the first polar body though it did not inhibit the rate of germinal vesicle breakdown of immature oocytes in vitro maturation.The BDE-209 has little impact on the activation rate of the oocytes.However,the BDE-209 showed a marked inhibition effects on the embryonic development.