A 5' 2-kilobase-pair region of the imprinted mouse H19 gene exhibits exclusive paternal methylation throughout development
A 5' 2-kilobase-pair region of the imprinted mouse H19 gene exhibits exclusive paternal methylation throughout development
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DOI：
10.1128/mcb.17.8.4322
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发表时间：
1997-08-01
影响因子：
5.3
通讯作者：
Bartolomei, MS
中科院分区：
文献类型：
--
作者：
Tremblay, KD;Duran, KL;Bartolomei, MS
印迹小鼠H19基因在体细胞组织和精子的非活性父本等位基因上高度甲基化，先前有限分析的观察结果表明，转录开始上游区域的几个CpG二核苷酸甲基化可能是赋予H19等位基因亲本身份的标志。在这里，我们利用亚硫酸盐诱变与基因组测序相结合，得出了位于4-kb区域5'到转录开始的68个CpGs的甲基化状态。该方法揭示了位于转录开始上游2- 4 kb的2-kb区域，该区域在妊娠中期胚胎中甲基化差异显著。在囊胚中，该区域至少有12个胞嘧啶残基在父系等位基因上完全甲基化。相比之下，在妊娠中期胚胎中，350 bp的启动子近端区域甲基化差异较小，并且与大多数基因组一样，囊胚中两个等位基因在很大程度上缺乏甲基化。我们还证实了母体H19等位基因在胚胎中独占表达，表现出父本上游2kb区域的甲基化。这些数据表明，2kb差异甲基化区域是印迹H19表达的关键调控区域。
The imprinted mouse H19 gene is hypermethylated on the inactive paternal allele in somatic tissues and sperm, Previous observations from a limited analysis have suggested that methylation of a few CpG dinucleotides in the region upstream from the start of transcription may be the mark that confers parental identity to the H19 alleles. Here we exploit bisulfite mutagenesis coupled with genomic sequencing to derive the methylation status of 68 CpGs that reside in a 4-kb region 5' to the start of transcription. This method reveals a 2-kb region positioned between 2 and 4 kb upstream from the start of transcription that is strikingly differentially methylated in midgestation embryos. At least 12 of the cytosine residues in this region are exclusively methylated on the paternal allele in blastocysts. In contrast, a 350-bp promoter-proximal region is less differentially methylated in midgestation embryos and, like most of the genome, is largely devoid of methylation on both alleles in blastocysts. We also demonstrate exclusive expression of the maternal H19 allele in the embryos that exhibit paternal methylation of the upstream 2-kb region. These data suggest that the 2-kb differentially methylated region acts as a key regulatory domain for imprinted H19 expression.