IVF results in de novo DNA methylation and histone methylation at an Igf2-H19 imprinting epigenetic switch
IVF results in de novo DNA methylation and histone methylation at an Igf2-H19 imprinting epigenetic switch
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DOI：
10.1093/molehr/gah230
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发表时间：
2005-09-01
影响因子：
4
通讯作者：
Hoffman, AR
中科院分区：
文献类型：
--
作者：
Li, T;Vu, TH;Hoffman, AR
最近的研究表明，IVF和辅助生殖技术（ART）可能会导致异常的基因组印记，导致IVF儿童中Angelman综合征（AS）和Beckwith-Weidemann综合征（BWS）的频率增加。为了了解ART如何改变表观基因组，我们检查了来自C57 BL/6 J X M的桑椹胚和囊胚。spretus F1小鼠在体内和体外受孕，并确定了四个印迹基因的等位基因表达：Igf 2，H19，Cdkn 1c和Slc 221 L。在人输卵管液（HTF）（Quinn's advantage）培养基中培养的IVF衍生小鼠胚胎显示出异常H19印迹的高频率，而体内和IVF胚胎显示出Cdkn 1c的正常母体表达和Igf 2和Slc 221 L的正常双等位基因表达。体外受精囊胚的胚胎干细胞（ES细胞）也表现出异常的Igf 2/H19印迹。等位基因特异性亚硫酸氢盐PCR揭示了印迹控制区（ICR）中CCCTC结合因子（CTCF）位点的异常DNA甲基化，因为通常未甲基化的母系等位基因获得了父系甲基化模式。染色质免疫沉淀（ChIP）试验表明，在相同的CTCF结合位点，父本染色质上赖氨酸4甲基化（二甲基赖氨酸4-H3）增加，母本染色质上赖氨酸9甲基化（三甲基赖氨酸9-H3）增加。我们的研究结果表明，在IVF衍生的ES细胞中，母体等位基因上的从头DNA甲基化和组蛋白甲基化的等位基因特异性获得导致异常Igf 2/H19印迹。我们认为，ART，其中包括IVF和各种培养基，可能会导致印迹错误，涉及异常的DNA甲基化和组蛋白甲基化在Igf 2-H19基因区域的表观遗传开关。
Recent studies suggest that IVF and assisted reproduction technologies (ART) may result in abnormal genomic imprinting, leading to an increased frequency of Angelman syndrome (AS) and Beckwith-Weidemann syndrome (BWS) in IVF children. To learn how ART might alter the epigenome, we examined morulas and blastocysts derived from C57BL/6J X M. spretus F1 mice conceived in vivo and in vitro and determined the allelic expression of four imprinted genes: Igf2, H19, Cdkn1c and Slc221L. IVF-derived mouse embryos that were cultured in human tubal fluid (HTF) (Quinn's advantage) media displayed a high frequency of aberrant H19 imprinting, whereas in vivo and IVF embryos showed normal maternal expression of Cdkn1c and normal biallelic expression of Igf2 and Slc221L. Embryonic stem (ES) cells derived from IVF blastocysts also showed abnormal Igf2/H19 imprinting. Allele-specific bisulphite PCR reveals abnormal DNA methylation at a CCCTC-binding factor (CTCF) site in the imprinting control region (ICR), as the normally unmethylated maternal allele acquired a paternal methylation pattern. Chromatin immunoprecipitation (ChIP) assays indicate an increase of lysine 4 methylation (dimethyl Lys4-H3) on the paternal chromatin and a gain in lysine 9 methylation (trimethyl Lys9-H3) on the maternal chromatin at the same CTCF-binding site. Our results indicate that de novo DNA methylation on the maternal allele and allele-specific acquisition of histone methylation lead to aberrant Igf2/H19 imprinting in IVF-derived ES cells. We suggest that ART, which includes IVF and various culture media, might cause imprinting errors that involve both aberrant DNA methylation and histone methylation at an epigenetic switch of the Igf2-H19 gene region.