Modulation of imprinted gene network in placenta results in normal development of in vitro manipulated mouse embryos
Modulation of imprinted gene network in placenta results in normal development of in vitro manipulated mouse embryos
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DOI：
10.1093/hmg/ddq059
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发表时间：
2010-05-01
影响因子：
3.5
通讯作者：
Jammes, Helene
中科院分区：
文献类型：
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作者：
Fauque, Patricia;Ripoche, Marie-Anne;Jammes, Helene
基因组印迹调控一组单等位基因的表达，这些基因以亲本来源的特定方式表达。等位基因特异性DNA甲基化发生在这些基因的差异甲基化区域(DMRS)。我们先前已经证明，体外受精和胚胎培养会导致胚泡阶段印记的H19-Igf2基因座的甲基化缺陷。目前的研究旨在评估这些操作对小鼠植入后基因组印迹的影响。囊胚的产生遵循三种实验条件：(1)体内受精后保存在培养液中的胚胎；(2)体外受精；(3)对照组，体内受精和定时交配后获得的胚胎。将囊胚全部移植到假孕母鼠体内。于发育第10.5天采集胚胎和胎盘。用定量焦磷酸测序法分析H19、Igf2、Igf2r和Dlk1-dio3DMR的DNA甲基化模式。与囊胚期相比，体外受精和培养后胚胎和胎盘组织中的甲基化特征都是正常的。用定量RT-PCR方法分析了最近报道的印记基因网络(IGN)中的一组印记基因(包括Igf2和H19)在胎盘组织中的表达。体外受精和胚胎培养后获得的胎盘显示出显著的H19和Igf2基因以及来自IGN的大多数其他基因的干扰水平。由于胚胎在表型上是正常的，我们假设印记基因的协调网络的调节导致了一个能够纠正胎盘潜在功能障碍的代偿过程。
Genomic imprinting regulates the expression of a group of genes monoallelically expressed in a parent-of-origin specific manner. Allele-specific DNA methylation occurs at differentially methylated regions (DMRs) of these genes. We have previously shown that in vitro fertilization and embryo culture result in methylation defects at the imprinted H19-Igf2 locus at the blastocyst stage. The current study was designed to evaluate the consequences of these manipulations on genomic imprinting after implantation in the mouse. Blastocysts were produced following three experimental conditions: (i) embryos maintained in culture medium after in vivo fertilization or (ii) in vitro fertilization and (iii) a control group with embryos obtained after in vivo fertilization and timed mating. Blastocysts were all transplanted into pseudopregnant females. Embryos and placentas were collected on day 10.5 of development. DNA methylation patterns of the H19, Igf2, Igf2r and Dlk1-Dio3 DMRs were analyzed by quantitative pyrosequencing. In contrast to blastocyst stage, methylation profiles were normal both in embryonic and placental tissues after in vitro fertilization and culture. Expression of a selected set of imprinting genes from the recently described imprinted gene network (IGN) (including Igf2 and H19) was analyzed in placental tissues by quantitative RT-PCR. Placentas obtained after in vitro fertilization and embryo culture displayed significantly disturbed levels of H19 and Igf2 mRNA, as well as of most other genes from the IGN. As embryos were phenotypically normal, we hypothesize that the modulation of a coordinated network of imprinted genes results in a compensatory process capable of correcting potential dysfunction of placenta.