Evaluation of endocrine disruptors using chicken fertilized egg

将不同剂量的己烯雌酚(DES)、壬基酚(NP)和双酚A(BPA)注射到鸡受精卵中，研究其对鸡受精卵孵化第7天存活率、孵化率和性腺发育的影响。高剂量DES(1 Mg)注射到卵中，存活率和孵化率均显著降低，出现了性反转雄性(表型雌性，无论是哪种类型的雄性，都有类似左侧性腺的卵巢)。虽然高剂量的NP或BPA(100 Mg)对鸡胚胎的发育也有毒性，但对雄性左侧睾丸进入卵巢没有影响。暴露于高剂量的DES、NP和BPA似乎对野生动物胚胎的发育是有害的。此外，还研究了双酚A和o，p‘-DDT对性别鉴定后的鹌鹑胚胎肝脏卵黄蛋白原(VTG II)基因表达的影响。RT-PCR法检测到对照组雄性和雌性小鼠肝脏中均未检测到VTGIImRNA的表达，而雌二醇17-β处理组大鼠肝脏中有明显的VTGIImRNA转录产物(183bp)。在双酚A处理组，VTG II在雌性胚胎有少量表达。然而，在雄性胚胎中没有检测到mRNA的诱导表达。O，p‘-DDT处理可显著诱导VTG II在雌性胚胎中的表达。此外，在所使用的剂量下，它还诱导雄性胚胎中VTG II的mRNA水平略有增加。这两种化学物质都有微弱的雌激素活性。综上所述，鸡受精卵可以用来评估具有雌激素活性的内分泌干扰物。BPA和o，p‘-DDT具有较弱的雌激素样作用。

Various doses of diethylstilbestrol(DES), nonylphenol(NP) and bisphenol A(BPA) were injected into chicken fertilized eggs, and the influences on the viability on day 7 of incubation, hatchability and development of the gonads were examined. Both the viability and hatchability were significantly lower, and a sex-reverse male (phenotypic female having ovary like left gonad regardless of genotypic male) appeared when high dose of DES (1mg) was injected to the eggs. Though high doses of NP or BPA (100mg) was also poisonous for the development of chicken embryos, they had no effect on the male left testis into the ovary. Exposure to high dose of DES, NP and BPA appear to be harmful to the development of embryos in wildlife. The effects of BPA and o,p'- DDT on mRNA expression of vitellogenin (VTG II) in the liver of quail embryo after their sexing were also investigated. RT-PCR analysis detected no mRNA expression of VTG II in the liver of males and females in the control group, whereas distinct VTG II mRNA transcripts were detected in the Estradiol 17β treated female and male groups (183 bp). In BPA treated group, there was a slight expression of VTG II in female embryos. However, no induction of mRNA expression was detected in male embryos. o,p'- DDT treatment induced a remarkable expression of VTG II in female embryos. Moreover, it induced a slight increase in the mRNA levels of VTG II in male embryos at the dose used. Both chemicals have weak estrogenic action.In conclusion, chicken fertilized eggs can be utilized to assess endocrine disruptors, which have estrogenic activity. BPA and o,p'-DDT have weak estrogenic action.