邻苯二甲酸二(2-乙己基)酯致小鼠睾丸基因组DNA甲基化水平变化分析

目的:探讨增塑剂邻苯二甲酸二(2-乙己基)酯(DEHP)作用于怀孕小鼠后,其仔代睾丸基因组DNA甲基化水平的改变情况。方法:妊娠KM小鼠随机分为3组:正常对照组、玉米油对照组和DEHP实验组。自妊娠12.5 d到生后第3天分别持续经口予以玉米油和DEHP[500 mg/(kg.d)],于生后第7天取仔代睾丸,应用甲基敏感扩增多态性(MSAP)技术,对仔鼠睾丸组织DNA进行EcoRⅠ/MspⅠ和EcoRⅠ/HpaⅡ两种酶切反应,经ABI 3730DNA自动测序仪电泳及检测后,运用Genescan3.1分析扩增谱带。结果:对CCGG位点,DEHP实验组小鼠仔代睾丸组织DNA甲基化程度明显增高,其甲基化水平为(34.03±3.05)%;而正常对照组和玉米油对照组小鼠仔代睾丸组织基因组DNA甲基化程度分别为(28.37±2.37)%和(28.58±2.45)%。DEHP实验组与正常对照组和玉米油对照组相比,差异具有统计学意义(P<0.05)。结论:DEHP作用孕鼠后可导致仔代睾丸基因组DNA甲基化水平改变,影响基因组表观遗传修饰改变,可能是导致生殖系统损害的重要毒理机制之一。

Di-(2-Ethylhexyl) Phthalate Increases the DNA Methylation Level of Genomes in the Mouse Testis

Objective： To investigate the effect of the exposure to di-（2-ethylhexyl） phthalate（DEHP） during pregnancy on the DNA methylation level of genomes in the testis of the offspring in mice.Methods： Pregnant KM mice were randomly divided into three groups,normal control,corn oil and DEHP-exposed.Corn oil and DEHP（500 mg/） were administrated respectively from gestation day 12.5（GD 12.5） to postnatal day 3（PND 3）.The testes of the offspring were excised on PND 7,and their genomic DNA was treated with EcoRⅠ/MspⅠ and EcoRⅠ/HpaⅡ.The genome-wide DNA methylation patterns of the CCGG sites were detected by methylation-sensitive amplification polymorphism（MSAP）.The samples were electrophoresed in the ABI 3730 DNA sequencer and the results analyzed by the Genescan3.1.Results： The average incidence of DNA methylation was（34.03±3.05）% in the DEHP-exposed mice,obviously higher than（28.37±2.37）% in the normal control and（28.58±2.45）% in the corn oil group,with statistically significant differences（P0.05）.Conclusion： Exposure to DEHP during pregnancy increases the DNA methylation level of the genome in the testis of the offspring and affects the apparent genetic modification of the genome,which may be one of the important toxicological causes of the lesion in the reproductive system.